Identify IC ?

N_Cook

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Mar 10, 2019, 12:06:55 PM3/10/19

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RIFAR540
RD6416 N
Could be 1 instead of I , and N probably refers to the plastic
encapsulation. 14 pin IC in the power supply section of some 1979 kit.

N_Cook

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Mar 10, 2019, 2:31:13 PM3/10/19

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Until I can power-up probe/explore trackside, my guess is perhaps , from
the "16", a variant of CMOS quad analogue sw.

N_Cook

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Mar 10, 2019, 5:13:31 PM3/10/19

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pins 1,3,5 and 13 seem of the same type or function, inputs or outputs
or control lines from another board, so could be quad an. sw.
A stepped range of supply volts or amps would make some sense for a
step-wise variable drive.

John Robertson

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Mar 11, 2019, 1:44:55 AM3/11/19

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UA/LM741 was a common regulator back then and came in a 14 pin DIP, but
it doesn't match your description of particular pins. Where is your
device relative to the pass transistor? Does it drive the base or the
[ass transistor or does it drive another transistor that perhaps drives
the base?

What equipment is it used in? You say some kit, more info may help if
one of us has the schematics...

John :-#)#

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Phil Allison

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Mar 11, 2019, 2:49:59 AM3/11/19

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John Robertson wrote:
>
>
>
> UA/LM741 was a common regulator back then and came in a 14 pin DIP,

** Huh ??

Surely you mean the uA/LM723 adjustable regulator.

The LM741 is a most famous op-amp.

... Phil

N_Cook

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Mar 11, 2019, 5:04:40 AM3/11/19

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On 11/03/2019 05:44, John Robertson wrote:
> On 2019/03/10 2:13 p.m., N_Cook wrote:
>> On 10/03/2019 18:31, N_Cook wrote:
>>> On 10/03/2019 16:06, N_Cook wrote:
>>>> RIFAR540
>>>> RD6416 N
>>>> Could be 1 instead of I , and N probably refers to the plastic
>>>> encapsulation. 14 pin IC in the power supply section of some 1979 kit.
>>>
>>> Until I can power-up probe/explore trackside, my guess is perhaps , from
>>> the "16", a variant of CMOS quad analogue sw.
>>>
>>
>> pins 1,3,5 and 13 seem of the same type or function, inputs or outputs
>> or control lines from another board, so could be quad an. sw.
>> A stepped range of supply volts or amps would make some sense for a
>> step-wise variable drive.
>
> UA/LM741 was a common regulator back then and came in a 14 pin DIP, but
> it doesn't match your description of particular pins. Where is your
> device relative to the pass transistor? Does it drive the base or the
> [ass transistor or does it drive another transistor that perhaps drives
> the base?
>
> What equipment is it used in? You say some kit, more info may help if
> one of us has the schematics...
>
> John :-#)#
>

The 14A of these EDM

<http://www.aga-museum.nl/page/geodimeter-model-12->

The external V reg for 12V car battery down to 6V failed decades ago ,
repairing that, there was still a fault inside.
Powering up these days all the amber nixie segments light on test,
signal LEDs light , servo neutral density filter rotates, a shutter
moves but no cue tone on the audio and simple IR phototransistor+red LED
zapper tester shows no IR output.
Getting inside and isolating (perhaps, not wanting to disturb the fixing
of the sub-board in its screened box as all optically aligned)
the Tx GaAs diode cold tests as likely functional.
Next thing (as 4 densely packed boards of TTL and CMOS and rather too
many "after-thought"/mod flying components including a 14 pin IC)
is fit back together , expanded with standoffs, to be able to probe the
PS area.
But stepped supply to the Tx diode makes operational sense.
The only tech material i've found is this general principles of
operation of such EDM of that time.
It has some provenance, owned by Ordnance Survey the premier map-makers
in the UK, until something went wrong with it and they entered it into
one of their then regular auctions of surplus stuff.

N_Cook

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Mar 11, 2019, 5:09:14 AM3/11/19

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On 11/03/2019 09:04, N_Cook wrote:
> The only tech material i've found is this general principles of
> operation of such EDM of that time.

omission

<http://www.sage.unsw.edu.au/sites/sage/files/SAGE_collection/MonographSeries/mono7.pdf>

N_Cook

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Mar 11, 2019, 9:12:19 AM3/11/19

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Harris semiconductor had a series run in 70s of RD*** and did loads of
an sw variants in 80s/90s, perhaps RD6416.
There is certainly 4 "channels" associated with it , a resistor
different values , BC107 pre-driver and a TO220 driver/pass transistor
repeated 4 times.

John Robertson

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Mar 11, 2019, 12:31:27 PM3/11/19

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> .... Phil
>
>

Thanks Phil, of course I meant the 723. That is why you should never
post after an evening of wine...

John :-#(#

Phil Allison

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Mar 11, 2019, 5:31:49 PM3/11/19

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John Robertson wrote:

>
> Phil Allison wrote:
> >
> >
> >>
> >> UA/LM741 was a common regulator back then and came in a 14 pin DIP,
> >
> >
> > ** Huh ??
> >
> > Surely you mean the uA/LM723 adjustable regulator.
> >
> > The LM741 is a most famous op-amp.
> >
>> >
> >
>

> Thanks Phil, of course I meant the 723. That is why you should never
> post after an evening of wine...
>

** Back in the early 1970s, I put together a bench PSU for myself using an LM723 plus 2N3055 pass transistor.

The 723 was in the then common TO100 round, gold lead pak.

https://gridchoice.com/shop/can-type/12455-ic-voltage-regulator-fairchild-u5r7723393-to100-10.html

I still have and use the PSU.

With the addition of a few upgrades, it does 2.2 to 20V at 2 amps with continuously variable current limit from 100mA up.

.... Phil

bruce2...@gmail.com

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Mar 17, 2019, 11:58:39 AM3/17/19

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But then, where's all the fun?

John Robertson

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Mar 17, 2019, 3:11:21 PM3/17/19

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OT:

An evening of wine and Midsomer Murders is the usual fun for a couple of
evenings a week with my wife...

John :-#)#