Here you go:
http://www.diyaudio.com/forums/blogs/dvb-projekt/561-sshv-shunt-module.html
Recommended!
As you need symmetric, you should go to the SSHV thread, there I have shown its negative mirror also that has been implemented by a few members successfully.
Can you be more specific or put the URL for that SSHV thread?
The first search I did here got me nothing named like that?
My first option for these regulators are with 3X7 types, and it seems that using two positive types 317s seem to have better impedance and noise specs.
So if I can accept two chip positives, why not two discrete ones?
Once again: that is if using symmetric HV shunts will not bring me any benefits. Will they?
So if I can accept two chip positives, why not two discrete ones?
Once again: that is if using symmetric HV shunts will not bring me any benefits. Will they?
Hi Andrew
Would you please elaborate on the benefits of using two negative regs besides the cost factor ?
I read a lot about the benefits of using two 317 based positive regs. The fixed negative series regs always show worst performance in the datasheets also.
So this is completely new to me (appart from your previous statements I read before).
Ricardo
Would you please elaborate on the benefits of using two negative regs besides the cost factor ?
I read a lot about the benefits of using two 317 based positive regs. The fixed negative series regs always show worst performance in the datasheets also.
So this is completely new to me (appart from your previous statements I read before).
Ricardo
Hi Salas,
I like this simple shunt design, and moreover I love how easily it is to get parts for this shunt locally here
I planned to build one v1.2R (pos and neg) in around 2 weeks from now after my schedule is a bit cleared up, but before, I have some questions, first, here's the plan:
Well, that's it, sorry for the long questions, anyways, you rocks!
I like this simple shunt design, and moreover I love how easily it is to get parts for this shunt locally here
I planned to build one v1.2R (pos and neg) in around 2 weeks from now after my schedule is a bit cleared up, but before, I have some questions, first, here's the plan:
- I'm going to use a small enclosure (roughly 10cm W x 16cm L x 6cm H), this enclosure will double as a heatsink, is 4mm thick aluminum and have additional fins (1cm deep i think) outside along the left and right side of it.
- The target output voltage is +/- 12V
- The set current on R1 will be adjustable for 100mA, 200mA, and 300mA load current respectively using a rotary switch
- I'm using the BJT CCS version simply because I can get a bag of BC550/560 for the price of one K170BL here...
- Toroid i'm using outputting 21V after rectification and filtering
- Will thermal drift be an issue for such a case above? i.e. temperature will cause change on Q9's current, thus changing the V drop across R11 and in effect making the Vref voltage drifting?
- If it will be a problem, can I revert back to the Vref from the v1.0, using a zener? If so, should I change the value of C1 back into 100uF or keep it at 4.7uF?
- On the case of using zener as Vref, what is the best scenario to put a trimmer to "fine tune" the output voltage (i.e. within 1V), so I can get exactly symmetrical voltage at +/- 12V, is it by using small value trimmer in series with the zener or somewhere else?
- What do you think is the best shunt current to load current ratio? i.e. 180mA through R1 for 80mA shunt current and 100mA load makes it 1:1.25 ratio...
Well, that's it, sorry for the long questions, anyways, you rocks!
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The SSHV in question uses shunt IRF840 NMOSFET for both polarities anyway.
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