MOSFET gate threashold voltage
Paul Burridge
Hi,
I'm carrying out some tests with a IRF7303 N-channel MOSFET. It
appears to start turning on at 2.3v and by 2.4v., it's fully
saturated. Does this seem right - even for MOSFETs in general? To my
mind it seems a bit on the low side.
p.
--
"What is now proved was once only imagin'd"
- William Blake, 1793
John Larkin
<red...@waitrose.notthisbit.com> wrote:
>
>Hi,
>
>I'm carrying out some tests with a IRF7303 N-channel MOSFET. It
>appears to start turning on at 2.3v and by 2.4v., it's fully
>saturated. Does this seem right - even for MOSFETs in general? To my
>mind it seems a bit on the low side.
>
>p.
What's the drain current? You may well need a lot more gate drive to
get it to saturate at higher currents.
John
Paul Burridge
<jjla...@highSNIPlandTHIStechPLEASEnology.com> opined thusly:
>On Fri, 18 Apr 2003 22:23:01 +0100, Paul Burridge
><red...@waitrose.notthisbit.com> wrote:
>
>>
>>Hi,
>>
>>I'm carrying out some tests with a IRF7303 N-channel MOSFET. It
>>appears to start turning on at 2.3v and by 2.4v., it's fully
>>saturated. Does this seem right - even for MOSFETs in general? To my
>>mind it seems a bit on the low side.
>>
>>p.
>
>What's the drain current?
0.01A.
>You may well need a lot more gate drive to
>get it to saturate at higher currents.
Clarification, please.
John Larkin
<red...@waitrose.notthisbit.com> wrote:
>On Fri, 18 Apr 2003 15:44:07 -0700, John Larkin
><jjla...@highSNIPlandTHIStechPLEASEnology.com> opined thusly:
>
>>On Fri, 18 Apr 2003 22:23:01 +0100, Paul Burridge
>><red...@waitrose.notthisbit.com> wrote:
>>
>>>
>>>Hi,
>>>
>>>I'm carrying out some tests with a IRF7303 N-channel MOSFET. It
>>>appears to start turning on at 2.3v and by 2.4v., it's fully
>>>saturated. Does this seem right - even for MOSFETs in general? To my
>>>mind it seems a bit on the low side.
>>>
>>>p.
>>
>>What's the drain current?
>
>0.01A.
>
>>You may well need a lot more gate drive to
>>get it to saturate at higher currents.
>
>Clarification, please.
Well, suppose you had a 20 volt V+ supply and ran a 10 ohm resistor
from there to the drain. Now as you apply positive gate voltage,
'saturation' will pull 2 amps of drain current. You'll find that you
need a lot more gate voltage to get the drain down near ground than if
you only had 10 mA available. Most normal fets are 'fully enhanced',
turned on about as hard as they'll ever get, at maybe 10-12 gate
volts. The low threshold 'logic fets' turn on a bit easier.
John
Paul Burridge
opined thusly:
>Paul Burridge wrote:
>>
>> On Fri, 18 Apr 2003 23:20:24 GMT, John Popelish <jpop...@rica.net>
>> opined thusly:
>>
>> >Paul Burridge wrote:
>> >>
>> >> Hi,
>> >>
>> >> I'm carrying out some tests with a IRF7303 N-channel MOSFET. It
>> >> appears to start turning on at 2.3v and by 2.4v., it's fully
>> >> saturated. Does this seem right - even for MOSFETs in general? To my
>> >> mind it seems a bit on the low side.
>> >
>> >What operating conditions define "saturated"?
>>
>> AFAIC, negligible voltage drop between source and drain.
>
>While what current passes between those leads?
Sorry, chaps, I've used the term "saturation" out of context. I now
remember that saturation for BJTs and MOSFETS is totally different. I
was using the BJT definition for it (as someone else has pointed out
already in this thread).
So let me rephrase: doesn't a gate voltage of 2.4v seem very little to
fully switch-on of a MOSFET? I'm simulating this in SPICE, btw.
Paul Burridge
<jjla...@highSNIPlandTHIStechPLEASEnology.com> opined thusly:
>Well, suppose you had a 20 volt V+ supply and ran a 10 ohm resistor
>from there to the drain. Now as you apply positive gate voltage,
>'saturation' will pull 2 amps of drain current. You'll find that you
>need a lot more gate voltage to get the drain down near ground than if
>you only had 10 mA available. Most normal fets are 'fully enhanced',
>turned on about as hard as they'll ever get, at maybe 10-12 gate
>volts. The low threshold 'logic fets' turn on a bit easier.
Okay, let's quote the specifics and see what you think. The supply
*is* 20v+ which is applied to the drain via a 2k resistor. At just
2.4v on the gate, the drain voltage has collapsed to be virtually the
same as the source (ground) potential. Given those more specific
circumstances, doesn't that gate voltage of 2.4 seem very low to have
achieved full switch-on for any MOSFET?
Kevin Aylward
No. Not if its a big one.!
20/2k is only 10ma. If ita a > 1A job, then not much more than the
threshold is going to get you 10ma. For example, the old 2sk135/2sj50
audio power mosfets will conduct 100ma with only 0.5V on the gate.
Kevin Aylward
sa...@anasoft.co.uk
http://www.anasoft.co.uk
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.
Winfield Hill
>
> So let me rephrase: doesn't a gate voltage of 2.4v seem
> very little to fully switch-on of a MOSFET?
No.
Although Power MOSFETs in fact work well at low currents,
manufacturers don't often include much data helpful for
their use at low currents. Furthermore most engineering
books don't give much guidance. That's why we provided
figure 3.14 in our book, which is a plot of the FET gate
voltage necessary to operate a Supertex VN01 1A n-channel
MOSFET over the range of 1nA to 2A. The plot also shows
the min/max gate voltage observed from measuring 20 parts
taken from 4 manufacturing runs spread over 2 years.
Although a VN01 FET requires 4 to 6V for operation at 1 to
2 amps, it only needs about 2.0V to operate at 10mA.
1uA 1.25V to 1.5V
10uA 1.45 to 1.65V
0.1mA 1.7 to 1.95V
1.0mA 1.8 to 2.05V
10mA 1.9 to 2.2V
100mA 2.9 to 3.1V
This small table gives an idea, but please study the graph
in our book for better understanding. Your IRF7303 FET is
a bit larger part, with 0.05 ohm Rds-ON, so running it at
10mA would be like running about 0.1mA in a our 8-ohm VN01.
If we assume scaled similar construction, your 7303 would
only need to about 1.8V conduct 10mA, and 2.4V would insure
the part was fully ON. However, we know more gate voltage
is required at low temperatures, some parts may need higher
voltages, and you may want the lower Rds that comes from
extra gate voltage. Furthermore IRF's 7303 data sheet specs
the 1mA gate threshold at 1.5 to 3.5V. This is a bit higher
than a VN01 at a similar current density. We can estimate
a maximum of 3.7V would still be "within spec" for your 7303
operating at for 10mA, although you might never actually
find a production IRF7303 part requiring this much voltage.
Thanks,
- Win
John Popelish
(snip)
> So let me rephrase: doesn't a gate voltage of 2.4v seem very little to
> fully switch-on of a MOSFET? I'm simulating this in SPICE, btw.
A mosfet with little voltage between source and drain acts a lot like
a variable resistor. So if you put a 10,000 ohm resistor in series
with it, it will look saturated (drop little of the drain supply
voltage) when its resistance falls to about 1k ohms. If you put a 10
ohm resistor in series with it, it won't look saturated till its
resistance falls to about 1 ohm. It is not at all unusual for the
resistance to start falling from the off state value with a gate to
source voltage of 2.4 volts. It would be quite unusual if the drain
to source resistance was as low as it could go with only that much
gate voltage. Most mosfets are not at their lowest drain to source
resistance till about 10 to 15 volts gate to source, and logic level
fets reach this condition with 5 or more volts.
--
John Popelish
nospam
>Okay, let's quote the specifics and see what you think. The supply
>*is* 20v+ which is applied to the drain via a 2k resistor. At just
>2.4v on the gate, the drain voltage has collapsed to be virtually the
>same as the source (ground) potential. Given those more specific
>circumstances, doesn't that gate voltage of 2.4 seem very low to have
>achieved full switch-on for any MOSFET?
MOSFETs are not switches there is no concept of being 'fully switched on'.
The specifications for the part you are simulating show a minimum gate
threshold voltage of 1v at 250uA. If anything 2.4v seems a bit high for
your 10mA.
Mike Elliott
Kevin Aylward wrote:
> Paul Burridge wrote:
>
>>On Fri, 18 Apr 2003 17:51:47 -0700, John Larkin
>><jjla...@highSNIPlandTHIStechPLEASEnology.com> opined thusly:
>>
>>
>>>Well, suppose you had a 20 volt V+ supply and ran a 10 ohm resistor
>>>from there to the drain. Now as you apply positive gate voltage,
>>>'saturation' will pull 2 amps of drain current. You'll find that you
>>>need a lot more gate voltage to get the drain down near ground than
>>>if you only had 10 mA available. Most normal fets are 'fully
>>>enhanced', turned on about as hard as they'll ever get, at maybe
>>>10-12 gate volts. The low threshold 'logic fets' turn on a bit
>>>easier.
>>
>>Okay, let's quote the specifics and see what you think. The supply
>>*is* 20v+ which is applied to the drain via a 2k resistor. At just
>>2.4v on the gate, the drain voltage has collapsed to be virtually the
>>same as the source (ground) potential. Given those more specific
>>circumstances, doesn't that gate voltage of 2.4 seem very low to have
>>achieved full switch-on for any MOSFET?
>
>
> No. Not if its a big one.!
>
> 20/2k is only 10ma. If ita a > 1A job, then not much more than the
> threshold is going to get you 10ma. For example, the old 2sk135/2sj50
> audio power mosfets will conduct 100ma with only 0.5V on the gate.
Paul, you can get current to trickle through a MOSFET with fairly low
gate-source voltage. To turn them on hard, fully-saturated at
significant current, requires more voltage. Vgs(on) from the datasheet
will give you an idea of the voltage required for the current specified,
and the surprisingly large unit-to-unit spread of typical devices. The
MOSFETs Kevin mentioned above are lateral-types, usually (always?)
Japanese-made, for use in audio power amps, a significantly large market
for devices in Asia. They possess lower Vgs(on) than the vertical types
manufactured by European and US mfgrs, the latter targeted at markets
where linearity is not critical, such as switching power supply apps.
The Japanese parts are designed for more linear operation, are available
with matching complementary versions, and have a negative temperature
coefficient down into the milliamp drain current region, which permits
easy paralleling for increased current-handling. However they do have
more internal Rds(on) resistance than the vertical types so they would
not be a good choice for high-current apps unless you do parallel
several. Vertical types have positive current tempco's (except at high
drain current), which make paralleling difficult, but lower internal
drain-source resistance, so one device might be able to do the job.
MikeE
Paul Burridge
opined thusly:
>Paul Burridge wrote...
>>
>> So let me rephrase: doesn't a gate voltage of 2.4v seem
>> very little to fully switch-on of a MOSFET?
>
> No.
Now that's what I like: a totally unambiguous answer. :-)
I forget what exactly is covered in your magnum opus sometimes, Win. I
really must endeavour to pay more attention!
Paul Burridge
<ke...@anasoft.co.uk> opined thusly:
>Paul Burridge wrote:
>> On Fri, 18 Apr 2003 17:51:47 -0700, John Larkin
>> <jjla...@highSNIPlandTHIStechPLEASEnology.com> opined thusly:
>>
>>> Well, suppose you had a 20 volt V+ supply and ran a 10 ohm resistor
>>> from there to the drain. Now as you apply positive gate voltage,
>>> 'saturation' will pull 2 amps of drain current. You'll find that you
>>> need a lot more gate voltage to get the drain down near ground than
>>> if you only had 10 mA available. Most normal fets are 'fully
>>> enhanced', turned on about as hard as they'll ever get, at maybe
>>> 10-12 gate volts. The low threshold 'logic fets' turn on a bit
>>> easier.
>>
>> Okay, let's quote the specifics and see what you think. The supply
>> *is* 20v+ which is applied to the drain via a 2k resistor. At just
>> 2.4v on the gate, the drain voltage has collapsed to be virtually the
>> same as the source (ground) potential. Given those more specific
>> circumstances, doesn't that gate voltage of 2.4 seem very low to have
>> achieved full switch-on for any MOSFET?
>
>No. Not if its a big one.!
>
>20/2k is only 10ma. If ita a > 1A job, then not much more than the
>threshold is going to get you 10ma. For example, the old 2sk135/2sj50
>audio power mosfets will conduct 100ma with only 0.5V on the gate.
Oh right. So the threshold voltage varies according to the circuit
conditions, does it? Clearly still a few holes in my mental model of
the blasted things.
Paul Burridge
opined thusly:
>MOSFETs are not switches there is no concept of being 'fully switched on'.
Are you nuts or is this some sort of theoretical fine-point you're
trying to make here?
John Larkin
<red...@waitrose.notthisbit.com> wrote:
>On Sat, 19 Apr 2003 15:28:47 +0100, nospam <nos...@nospam.invalid>
>opined thusly:
>
>>MOSFETs are not switches there is no concept of being 'fully switched on'.
>
>Are you nuts or is this some sort of theoretical fine-point you're
>trying to make here?
Mosfets are linear analog devices. They have no hysteresis, and do not
snap on or off. They have no "threshold" unless you arbitrarily define
some drain current that is, in your opinion, "on".
You can use a mosfet as a switch, provided you apply lots of gate
drive, fast. Same as with a tube.
Relays, SCRs and thyratrons are true switches... transistors, fets,
and tubes are not.
John
Kevin Aylward
Not really. The threshold voltage is a somewhat arbitrary voltage. A mos
conducts below its threshold, but not much. One arbitrarily selects some
current level, e.g. 100na, 1ua, 10ua etc, and whatever the Vgs is to get
that, is the threshold voltage. Ok, in practise for spice model
simulation, the threshold might be wiggled a bit to get a better match
of the graph over all regions, but the point is that there is no real
deterministic point where I=0 for Vgs < Vth.
Winfield Hill
>
> I forget what exactly is covered in your magnum opus
> sometimes, Win. I really must endeavour to pay more
> attention!
Judging from your questions, you need to study
(re-read?) chapter three. :>)
Thanks,
- Win
Paul Burridge
thusly:
>Mosfets are linear analog devices. They have no hysteresis, and do not
>snap on or off. They have no "threshold" unless you arbitrarily define
>some drain current that is, in your opinion, "on".
>
>You can use a mosfet as a switch, provided you apply lots of gate
>drive, fast. Same as with a tube.
>
>Relays, SCRs and thyratrons are true switches... transistors, fets,
>and tubes are not.
Nevertheless, nospam stated that there's no concept of theme being
"fully switched on" whereas the data sheets commonly quote figures for
Rds(on) in the milliohm region. I'd say that's effectively switched
on!
Paul Burridge
opined thusly:
> Judging from your questions, you need to study
> (re-read?) chapter three. :>)
I think I need to re-read the whole book! :-(
nospam
You still seem not to understand how MOSFETs work.
MOSFETs are not switches they are linear(ish) transconductance devices.
A given gate voltage allows a proportional drain to source current to flow.
There is no concept of being fully switched on, only of being on enough to
pass current X.
Apply your 2.4v gate voltage and change your drain load resistance from 20k
to 1R then check how 'fully switched on' it is.
Fred Bartoli
"nospam" <nos...@nospam.invalid> a écrit dans le message news:
bne8av47qa6h0ned7...@4ax.com...
and draw two load lines :
- one with your 2K load and 20V supply
- the other with a 10 ohms load and still 20V supply
and look at what happens.
Oh, you know how to draw some load line, don't you ?
Fred.
Paul Burridge
opined thusly:
>You still seem not to understand how MOSFETs work.
Yeah, but I'm working on it. :-)
>MOSFETs are not switches they are linear(ish) transconductance devices.
Yep, I'm aware that they *can* be used for high quality amplification
given appropriate device and correct biasing within the relevant
region of operation. But if I want to do that, I'll use a trannie,
thanks all the same.
>A given gate voltage allows a proportional drain to source current to flow.
>There is no concept of being fully switched on, only of being on enough to
>pass current X.
>
>Apply your 2.4v gate voltage and change your drain load resistance from 20k
>to 1R then check how 'fully switched on' it is.
Yes, all fair comment, but let's face facts: the main use of power
mosfets is in *switching* high currents.
:P
Paul Burridge
<fred.bartoli...@free.removethis.fr.invalid> opined thusly:
>Or, in other words, take your fet ID vs VDS (with VGS as parameter) curves
>and draw two load lines :
>
>- one with your 2K load and 20V supply
>- the other with a 10 ohms load and still 20V supply
>
>and look at what happens.
>Oh, you know how to draw some load line, don't you ?
Yes, I do, thanks. The point about load is taken, anyway.
Winfield Hill
>
> nospam opined thusly:
>
>> You still seem not to understand how MOSFETs work.
>
> Yeah, but I'm working on it. :-)
>
>> MOSFETs are not switches they are linear(ish) transconductance devices.
>
> Yep, I'm aware that they *can* be used for high quality amplification
> given appropriate device and correct biasing within the relevant
> region of operation. But if I want to do that, I'll use a trannie,
> thanks all the same.
>
>> A given gate voltage allows a proportional drain to source current to
>> flow. There is no concept of being fully switched on, only of being
>> on enough to pass current X.
>>
>> Apply your 2.4v gate voltage and change your drain load resistance
>> from 20k to 1R then check how 'fully switched on' it is.
>
> Yes, all fair comment, but let's face facts: the main use of power
> mosfets is in *switching* high currents.
Paul, seriously now, I think you have a _great_ deal to learn about
MOSFETs before you start lecturing us on their properties and use,
and how to characterize and think about them. You know what I mean.
Thanks,
- Win
Jim Thompson
wrote:
What do you mean, Win ?:-)
...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| Jim-T@analog_innovations.com Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |
For proper E-mail replies SWAP "-" and "_"
Democrats, The Axis of the Evil Empire
Winfield Hill
>
> What do you mean, Win ? :-)
OK, I'll explain. In my experience, an engineer does not learn
how to analyze the performance and operational characteristics
of any "digital" circuit element, especially a power MOSFET,
without a thorough understanding and analysis of its analog
properties. Digital state transitions and the static conditions
that follow are properly analyzed as analog events. In reality
there is no ON and OFF, except under the special condition of a
variety of assumptions, some commonly understood, and others not,
and most of limited validity. So there! :>)
Thanks,
- Win
John Fields
---
Ultimately, the on-ness or off-ness of a circuit can be determined by
the presence or absence of a single electron, so there goes your
precious analog jello. At the bottom it's all grits, and maybe a little
butter, so there!, right back atcha.
Winfield Hill
>
> Ultimately, the on-ness or off-ness of a circuit can be determined
> by the presence or absence of a single electron, so there goes your
> precious analog jello. At the bottom it's all grits, and maybe a
> little butter, so there!, right back atcha.
Nah, I don't truck by that there single-electron stuff. It takes
at least 150,000 electrons to get my digital-logic juices flowing.
Calculation:
q = C V = 0.05pF (min) * 0.5V (min) = 25fC, an amount
of charge that is q/e = 156250 electrons.
Thanks,
- Win
Paul Burridge
> Paul, seriously now, I think you have a _great_ deal to learn about
> MOSFETs before you start lecturing us on their properties and use,
> and how to characterize and think about them. You know what I mean.
Whoa! I'm not in a position to "lecture" *anyone* on this subject and
wasn't attempting to as you must surely know. I'm simply quoting what
most of my books say. For example, this one from 'Spice' 2nd edition
(Roberts & Sedra) at Sect.5.7:
"MOSFETs are commonly used as switches for both analogue and digital
signals. In analogue circuit applications a switch is used to control
the passage of an analogue current between two nodes in a circuit in
either direction without distortion or attenuation."
From 'Electronic Principles' (Malvin o) 6th ed. at page 467:
"The enhancement mode MOSFET is widely used in both discrete and
integrated circuits. In discrete circuits, the main use is in power
switching, which means turning large currents on and off. In
integrated circuits, the main use is in digital switching, the basic
process behind modern computers."
Those are the only books I have within arm's reach. If the authors are
wrong, then I'd be interested to *learn* why, because that and that
alone is what I'm here for!
Mike Engelhardt
It's even more analog than that. Individual electrons are significant
in an environment like a vacuum. But in a conductor, their wave
functions over lap, making their collective behavior more like
continuous.
For example. Consider the current in a wire and the number of electrons
per second to which that current corresponds. Discrete electron
statistics would suggest that a minim rms noise per second associated
with that current would be the square root of that number of electrons
that flow in one second. But solid state circuits are often much
quieter then that because the electron wave functions overlap.
--Mike
Jim Thompson
Paul,
Why don't you "curve-trace" an MOS device? Best would be in the lab,
but a simulation will do.
You are not allowed to call yourself an engineer until you've "smoked"
at least 100 circuits *and* understand why they "smoked" ;-)
Jonathan Kirwan
<pm...@concentric.net> wrote:
Win has mentioned that detail, obliquely, in his (and Paul's)
AofE.
And don't forget superconductors where the electrons of opposite
spins over a number of atomic distances are entangled into
spin-0 bosons.
Jon
Winfield Hill
>
> It's even more analog than that. Individual electrons are significant
> in an environment like a vacuum. But in a conductor, their wave
> functions over lap, making their collective behavior more like
> continuous.
>
> For example. Consider the current in a wire and the number of electrons
> per second to which that current corresponds. Discrete electron
> statistics would suggest that a minim rms noise per second associated
> with that current would be the square root of that number of electrons
> that flow in one second. But solid state circuits are often much
> quieter then that because the electron wave functions overlap.
Right, the current generated by a resistor and a dc voltage doesn't
have any shot noise, as we first pointed out in AoE 24 years ago.
But of course it still has Johnson noise, i = (4kT/R)^1/2
Thanks,
- Win
Kevin Aylward
> On 22 Apr 2003 15:13:24 GMT, "Mike Engelhardt"
>
> And don't forget superconductors where the electrons of opposite
> spins over a number of atomic distances are entangled into
> spin-0 bosons.
>
Spin 1 bosons.
Kevin Aylward
> Jonathan Kirwan wrote:
>> On 22 Apr 2003 15:13:24 GMT, "Mike Engelhardt"
>
>>
>> And don't forget superconductors where the electrons of opposite
>> spins over a number of atomic distances are entangled into
>> spin-0 bosons.
>>
>
> Spin 1 bosons.
>
Well, I suppose spin zero is a boson as well...I tend to think on 1 for
photons and 2 for gravitons.
Jonathan Kirwan
<ke...@anasoft.co.uk> wrote:
>Jonathan Kirwan wrote:
>> On 22 Apr 2003 15:13:24 GMT, "Mike Engelhardt"
>
>>
>> And don't forget superconductors where the electrons of opposite
>> spins over a number of atomic distances are entangled into
>> spin-0 bosons.
>>
>
>Spin 1 bosons.
It's an interesting lattice interaction, which I believe was
first described by Cooper, and they *are* spin-0 (anti-symmetric
in spin, so the angular momentum sums to zero) bosons (Cooper
pairs) which opposite momentums. This doesn't *have* to be the
case. But at least, so far, it appears to be. There *is* some
thought that, in high-T superconductors, they may form spin-2
bosons. But, at last blink, I don't think it's a decided issue.
A massive (as opposed to a massless) spin-1 boson has three
degrees of freedom (in the massless case, such as a photon,
gauge symmetry is exploited to eliminate one of the polarization
states, since it is traveling at the speed of light.) Cooper
pairs with spin-1 may actually attract or repel each other,
while spin 0 don't interact that way. That might result in a
very interesting superfluid of a non-trivial topo-order, but I
haven't thought about it.
An interesting thing crosses my mind about spin-2, if it turns
out correct in high-T superconductors, is that spin-2 massive
boson particles would necessarily attract. (Gravitons are
spin-2.) But I've got to think about the massive part of that
more.
Jon
Paul Burridge
<Jim-T@analog_innovations.com> opined thusly:
>Paul,
>
>Why don't you "curve-trace" an MOS device? Best would be in the lab,
>but a simulation will do.
Excellent suggestion, Jim. And I have been doing that when time
permits. As you say, it's highly instructive.
>You are not allowed to call yourself an engineer until you've "smoked"
>at least 100 circuits *and* understand why they "smoked" ;-)
Bugger, I'm only half-way there, then. :-)
No seriously, this has only ever been a fascinating hobby for me and I
have no aspirations beyond that - too bloody old anyway! ;-)
Andreas Hadler
>You are not allowed to call yourself an engineer until you've "smoked"
>at least 100 circuits *and* understand why they "smoked" ;-)
ROTFL!
May I
... call me a professional when I'm up to 250?
... put this in my sig-file?
Andreas
--
"You'll learn more between the legs of a good woman than any
university or college"
Jim Thompson
<Andreas...@t-online.de> wrote:
>Jim Thompson <Jim-T@analog_innovations.com> wrote:
>
>>You are not allowed to call yourself an engineer until you've "smoked"
>>at least 100 circuits *and* understand why they "smoked" ;-)
>
>ROTFL!
>
>May I
>... call me a professional when I'm up to 250?
>... put this in my sig-file?
>
>Andreas
Of course!
By that ranking method I'm up to "engineer emeritus" ;-)
Plus, if you count all the pranks I've pulled on my junior engineers,
I've reached the status of "engineer angel".
Winfield Hill
>
> if you count all the pranks I've pulled on my junior engineers,
> I've reached the status of "engineer angel".
Isn't that "engineer demon" ??
Thanks,
- Win
Jim Thompson
wrote:
>Jim wrote...
Could be ;-)
The most fun is to be had by fixing a breadboard while junior engineer
has gone to lunch.
Fix the mis-wire and then try to keep a straight face when junior
engineer returns and he starts cussing... "the damned thing is working
now" ;-)
qrk
<Jim-T@analog_innovations.com> wrote:
>On Tue, 22 Apr 2003 23:21:31 +0200, Andreas Hadler
><Andreas...@t-online.de> wrote:
>
>>Jim Thompson <Jim-T@analog_innovations.com> wrote:
>>
>>>You are not allowed to call yourself an engineer until you've "smoked"
>>>at least 100 circuits *and* understand why they "smoked" ;-)
>>
>>ROTFL!
>>
>>May I
>>... call me a professional when I'm up to 250?
>>... put this in my sig-file?
>>
>>Andreas
>
>Of course!
>
>By that ranking method I'm up to "engineer emeritus" ;-)
>
>Plus, if you count all the pranks I've pulled on my junior engineers,
>I've reached the status of "engineer angel".
>
> ...Jim Thompson
Don't you mean "engineer devil"?
Mark
Jim Thompson
wrote:
Mark, Win beat you to it with "engineer demon" ;-)
Winfield Hill
>
> Mark wrote:
>
>> Don't you mean "engineer devil"?
>
So we're all agreed then?
Thanks,
- Win
Jim Thompson
wrote:
>Jim wrote...
I'm actually quite the Teddy Bear. After any prank I gave a lesson in
what was really going on with their circuit.
I'm only dangerous to those who bad-mouth the good ol' US of A.
Chuck Harris
I thought we were all "demon engineers".
-Chuck
Winfield Hill
>
> Win wrote:
>> Jim wrote...
>>> Mark wrote:
>>>
>>>> Don't you mean "engineer devil"?
>>>
>>> Mark, Win beat you to it with "engineer demon" ;-)
>>
>> So we're all agreed then?
>
In that we design demons, yes.
Thanks,
- Win