Help from Allen Wright SuperReg owner

[pchw]

I just got 2 used SuperReg partially filled boards with only a few doc. I understand that this is Allen's commercial product. So, I won't go too far to discuss about the circuit. I just wanted to confirm the parts that I am going to use are correct.

1. According to one of the doc which is an email from Allen, I think these boards were no newer than 2002, and another doc is a silkscreen of the board that has some parts values. The opamp (IC2) is LF351 which can be purchased but probably low on performance. An suggestion for a replacement?
2. Is C5 used. These is no value in the silkscreen.
3. Is R1 1 meg? One of the boards stuffed 2 x 1-meg in series which makes it a
2-meg. The other board has nothing there.
4. Is C10 47uF/63V? In it's place, there is a 10pF ......
5. The ground trace of pin 4 of the opamp is cut, not sure why. I suppose it shouldn't
be that way, correct?

Thanks!!

 

[pchw]

By looking at the picture in Allen's site, I am able to answer Q2, Q3, and Q4. Common sense also tells me that cut trace in Q5 shouldn't be done that way.
For Q1, I found another member mentioned AD797 to replace the lowly LF351. So a little bump to see anyone can help on whichever opamp I can use instead of the LF351?

Thanks!!

 

[planet10]

Have you directly contacted Allen? Given you own his boards he'd probably help you out with at least the docs...

In the cookbook he talks about upgradng the op-amp but to be careful with oscillation... another trick i've heard mentioned is replacing the LM317 with a resister after the current has been dialed in in your circuit.

dave

 

[pchw]

Hi Dave,

The seller did provide me a copy of the LM31T mod which has Allen's
email for how to replace the LM317T with a resistor.
I will try contacting Allen again and hope the email will come through.

Thanks,