All PCBs shipped and tracking numbers sent by email.
All credit to the office staff in HK.
Patrick
All credit to the office staff in HK.
Patrick
For the 1 Ohm resistor wouldn't a current sense resistor like this work OK? http://www.mouser.com/ds/2/414/LR-469703.pdf 10 cents vs. $20. If its about low noise I think the excess noise of any 1 Ohm resistor at 1 mA will be in the mud anyway.
If there is a next run of boards I'll be interested.
If there is a next run of boards I'll be interested.
the value of C5 is way too low. it should have an low impedance for noise in series with the source, so similar to the 1 ohms resistor it's impedance should be low.
now it is 1.5k at 100 hz.
now it is 1.5k at 100 hz.
I think we still have ~5 boards left.
Take a week to order more. So no issue.
Getting someone to check payment, pack and ship is more troublesome.
Patrick
Take a week to order more. So no issue.
Getting someone to check payment, pack and ship is more troublesome.
Patrick
We also built a special version where the JFET is replaced by a TO92 test socket.
The latter sits on a stackered board which provides mechanical support.
We used a Version 1 board which had a layout error, so no use otherwise.
Now we can screen JFETs for noise. 😉
Patrick
The latter sits on a stackered board which provides mechanical support.
We used a Version 1 board which had a layout error, so no use otherwise.
Now we can screen JFETs for noise. 😉
Patrick
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While we are at it, may I also send you one (as a small gift from XEN), Scott ?
Your postal address is still as before ?
Patrick
Your postal address is still as before ?
Patrick
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If you are going to test a lot of devices, a good idea to replace R3 with a potentiometer and a series resistor, as you did to limit the current into the opto-coupler's LED (with R2a).
I'll get you my address since I'm retired now. They removed my email account even though someone went to great lengths for that not to happen.