4quadrant current source
DuFre
controlled current source, with on each side a capacitor. The current
can be 2way, so from C1->C2 and C1<-C2, independant of the voltage of
the caps.
So, the schematic looks something like:
GND---C1---CurSoure---C2---GND
Thanks, Fre
Tony Williams
Questions;
1. +/- I-peak?
2. Do you need a DC capability?
3. What is the AC frequency response?
4. +/- Vmax across C1 and C2?
5. Max differential voltage, C1-C2?
6. Whatever else I've forgotten atm.
--
Tony Williams.
Win Hill
Well, it's not hard to solve your problem by making two 4-quadrant
(source/sink at any voltage) current sources and programming one to
be the complement of the other, thereby effectively simulating the
completely-floating current source you show above.
GND---C1---CurSource CurSource---C2---GND | |
program -----+---|>o----'
voltage G = -1 inverter
Why do you need such a beast?
Thanks,
- Win
Tony Williams
Win Hill <wh...@picovolt.com> wrote:
> GND---C1---CurSource CurSource---C2---GND | |
> program -----+---|>o----'
> voltage G = -1 inverter
If it's within +/- 1mA/10V I have some dual OTA's
that are just itching to have some electrons
flowing in their veins.........
--
Tony Williams.
Win Hill
> Win Hill <wh...@picovolt.com> wrote:
>
>> GND---C1---CurSource CurSource---C2---GND
>> | |
>> program -----+---|>o----'
>> voltage G = -1 inverter
>
> If it's within +/- 1mA/10V I have some dual OTA's
> that are just itching to have some electrons
> flowing in their veins.........
Indeed, or if it's within the range of +/-2 to 10A
and +/-20 to 50V maximum, a few copies of the elegant
circuit you dreamed up here on s.e.d. a few years back
(which I expanded a bit) can be put to use.
----------------------------------------------------
Date: Thu, 24 Aug 2000 00:35:15 GMT
From: Win Hill <wh...@mediaone.net>
Organization: Rowland Institute for Science
Newsgroups: sci.electronics.design
Frank Bemelman wrote:
>
> Putting another inductor in series with the power supply ?
OK, but this new inductor better not saturate. How about using a
high-current version of Tony William's open-loop transconductance
(current-output) amplifier (see "Constant Current AC PSU,") below:
+Vs +--------+--------------------+---------+
| | | |
\ 5R \ | |
/ 680R 5W / 7V pk |
\ \ | |
| |E | |
D\|/ +----+-----+ |
D\|/ B | pnp | |
+--------------+|darlington| |
c\| |heat sink | |
npn|----------+ +----+-----+ |
e/| | |C |+
680R | | | ===
Vin +-/\/\--+---|\ 2k | | |
7V pk | | >-\/\/-+ +--[LOAD]-+
| ,-|/ | | |+
|0V | | ===
| | | |
e\| | |C |
pnp|----------+ +----+-----+ |
c/| | npn | |
+--------------+|darlington| |
D\|/ B |heat sink | |
D\|/ +----+-----+ |
| |E | |
\ 5R \ | |
/ 680R 5W / 7V pk |
\ \ | |
| | | |
-Vs +--------+--------------------+---------+
Reduce the supply voltage and change the 5-ohm resistor to say 1.0
ohm for use at currents up to 10A. You can also add my (untested)
improvement ideas if you desire - higher frequency response and 10%
class-A bias.
+Vs +--------+-----+----+------------+---------+
| | | | |
100R pot | | 5R00 \ |
| | | 5W / |
953 | | \ |
| | | |E |
D\|/ | |/ +----+-----+ |
+---------|npn B | pnp | |
| | |\e--+--+|darlington| |
| | | |heat sink | |
| 10k etc. | +----+-----+ |
| | | |C |+
c\| | | | ===
npn|----+-, | | | BFC
e/| | D | | |
| \|/ | | |
1k00 | | | |
1k00 | \|/ power | |
Vin +-/\/\--+--|\ | resistor | |
7V pk | | >- + | +--[LOAD]-+
| |/ | | | |
and etc for neg portion
Thanks,
- Win
John Fields
---
For free?
Count me out.
---
John Fields
Professional circuit designer
http://www.austininstruments.com
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