~60V shunt regulator... or not?

Nov 30, 2019 7 Replies
D

I recently bought one of these:

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30.html which requires up to 70V input. I've made this circuit from an old UPS transformer and junk box parts:
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$+1+0.000005+19.867427341514983+50+5+43%0Av+16+208+16+336+0+1+50+44+0+0+0.5%0Ad+128+208+192+144+2+default%0Ac+400+208+400+304+0+0.008+41.72364866364812%0Ac+400+352+400+432+0+0.008+42.77812458710309%0Aw+16+208+16+112+0%0Aw+16+112+192+112+0%0Aw+192+112+192+144+0%0Aw+16+336+16+352+0%0Aw+16+352+192+352+0%0Aw+192+352+192+272+0%0Aw+256+208+400+208+0%0Aw+400+304+400+352+0%0Aw+400+352+192+352+0%0Aw+400+432+400+464+0%0Aw+400+464+96+464+0%0Aw+96+464+96+208+0%0Aw+96+208+128+208+0%0Ar+528+208+528+464+0+100%0Aw+400+208+528+208+0%0Aw+400+464+528+464+0%0Ad+128+208+192+272+2+default%0Ad+192+272+256+208+2+default%0Ad+192+144+256+208+2+default%0Ax+578+343+623+346+4+24+load%0Ao+17+64+0+4099+160+1.6+0+2+17+3%0Ao+0+64+0+4099+80+102.4+1+2+0+3%0A

...the output of which is a bit too high. Is there a better/more elegant wa y of dropping the ~20V than this:

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$+1+0.000005+5.459815003314424+50+5+43%0Av+16+208+16+336+0+1+50+44+0+0+0.5%0Ad+128+208+192+144+2+default%0Ac+400+208+400+304+0+0.008+34.63745142580208%0Ac+400+352+400+432+0+0.008+42.30090430961934%0Aw+16+208+16+112+0%0Aw+16+112+192+112+0%0Aw+192+112+192+144+0%0Aw+16+336+16+352+0%0Aw+16+352+192+352+0%0Aw+192+352+192+272+0%0Aw+256+208+400+208+0%0Aw+400+304+400+352+0%0Aw+400+352+192+352+0%0Aw+400+432+400+464+0%0Aw+400+464+96+464+0%0Aw+96+464+96+208+0%0Aw+96+208+128+208+0%0Ar+624+208+624+464+0+10%0Ad+128+208+192+272+2+default%0Ad+192+272+256+208+2+default%0Ad+192+144+256+208+2+default%0At+544+240+544+208+1+1+-14.911177145175344+0.8210887654686729+10000%0A34+33v-zener+0+1.7143528192810002e-7+0+2+62%0Az+544+352+544+304+2+33v-zener%0Aw+560+208+624+208+0%0Aw+400+208+464+208+0%0Aw+464+208+528+208+0%0Aw+400+464+544+464+0%0Aw+544+464+624+464+0%0Ax+668+349+713+352+4+24+load%0Aw+544+352+544+464+0%0Aw+464+240+464+208+0%0Ar+464+240+464+304+0+1000%0Aw+544+304+544+240+0%0Aw+464+304+544+304+0%0Ao+17+64+0+4099+80+6.4+0+2+17+3%0Ao+0+64+0+4099



+80+102.4+1+2+0+3%0A ? The load will vary, I suppose between about 10 ohms and infinity, depending on settings on the RD6006.
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B

70V input. I've made this circuit from an old UPS tran sformer and junk box parts:
formatting link
$+1+0.000005+19.867427341514983+50+5+43%0Av+16+208+16+336+0+1+50+44+0+0+0.5%0Ad+128+208+192+144+2+default%0Ac+400+208+400+304+0+0.008+41.72364866364812%0Ac+400+352+400+432+0+0.008+42.77812458710309%0Aw+16+208+16+112+0%0Aw+16+112+192+112+0%0Aw+192+112+192+144+0%0Aw+16+336+16+352+0%0Aw+16+352+192+352+0%0Aw+192+352+192+272+0%0Aw+256+208+400+208+0%0Aw+400+304+400+352+0%0Aw+400+352+192+352+0%0Aw+400+432+400+464+0%0Aw+400+464+96+464+0%0Aw+96+464+96+208+0%0Aw+96+208+128+208+0%0Ar+528+208+528+464+0+100%0Aw+400+208+528+208+0%0Aw+400+464+528+464+0%0Ad+128+208+192+272+2+default%0Ad+192+272+256+208+2+default%0Ad+192+144+256+208+2+default%0Ax+578+343+623+346+4+24+load%0Ao+17+64+0+4099+160+1.6+0+2+17+3%0Ao+0+64+0+4099+80+102.4+1+2+0+3% 0A

there a better/more elegant way of dropping the ~20V than this:

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$+1+0.000005+5.459815003314424+50+5+43%0Av+16+208+16+336+0+1+50+44+0+0+0.5%0Ad+128+208+192+144+2+default%0Ac+400+208+400+304+0+0.008+34.63745142580208%0Ac+400+352+400+432+0+0.008+42.30090430961934%0Aw+16+208+16+112+0%0Aw+16+112+192+112+0%0Aw+192+112+192+144+0%0Aw+16+336+16+352+0%0Aw+16+352+192+352+0%0Aw+192+352+192+272+0%0Aw+256+208+400+208+0%0Aw+400+304+400+352+0%0Aw+400+352+192+352+0%0Aw+400+432+400+464+0%0Aw+400+464+96+464+0%0Aw+96+464+96+208+0%0Aw+96+208+128+208+0%0Ar+624+208+624+464+0+10%0Ad+128+208+192+272+2+default%0Ad+192+272+256+208+2+default%0Ad+192+144+256+208+2+default%0At+544+240+544+208+1+1+-14.911177145175344+0.8210887654686729+10000%0A34+33v-zener+0+1.7143528192810002e-7+0+2+62%0Az+544+352+544+304+2+33v-zener%0Aw+560+208+624+208+0%0Aw+400+208+464+208+0%0Aw+464+208+528+208+0%0Aw+400+464+544+464+0%0Aw+544+464+624+464+0%0Ax+668+349+713+352+4+24+load%0Aw+544+352+544+464+0%0Aw+464+240+464+208+0%0Ar+464+240+464+304+0+1000%0Aw+544+304+544+240+0%0Aw+464+304+544+304+0%0Ao+17+64+0+4099+80+6.4+0+2+17+3%0Ao+0+64+0+4099+80+102.4+1+2+0+3%0A

oad will vary, I suppose between about 10 ohms and inf inity, depending on settings on the RD6006.

Pea k power dissipation in the transistor is well over 100 watts with a

10 ohm load, feeding a high efficiency converter box with a thing on a big-ass heatsink se ems a bit pathological
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D

551930.html which requires up to 70V input. I've made this circuit from an old UPS transformer and junk box parts:
formatting link
$+1+0.000005+19.867427341514983+50+5+43%0Av+16+208+16+336+0+1+50+44+0+0+0.5%0Ad+128+208+192+144+2+default%0Ac+400+208+400+304+0+0.008+41.72364866364812%0Ac+400+352+400+432+0+0.008+42.77812458710309%0Aw+16+208+16+112+0%0Aw+16+112+192+112+0%0Aw+192+112+192+144+0%0Aw+16+336+16+352+0%0Aw+16+352+192+352+0%0Aw+192+352+192+272+0%0Aw+256+208+400+208+0%0Aw+400+304+400+352+0%0Aw+400+352+192+352+0%0Aw+400+432+400+464+0%0Aw+400+464+96+464+0%0Aw+96+464+96+208+0%0Aw+96+208+128+208+0%0Ar+528+208+528+464+0+100%0Aw+400+208+528+208+0%0Aw+400+464+528+464+0%0Ad+128+208+192+272+2+default%0Ad+192+272+256+208+2+default%0Ad+192+144+256+208+2+default%0Ax+578+343+623+346+4+24+load%0Ao+17+64+0+4099+160+1.6+0+2+17+3%0Ao+0+64+0+4099+80+102.4+1+2+0+3%0 A

t way of dropping the ~20V than this:

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$+1+0.000005+5.459815003314424+50+5+43%0Av+16+208+16+336+0+1+50+44+0+0+0.5%0Ad+128+208+192+144+2+default%0Ac+400+208+400+304+0+0.008+34.63745142580208%0Ac+400+352+400+432+0+0.008+42.30090430961934%0Aw+16+208+16+112+0%0Aw+16+112+192+112+0%0Aw+192+112+192+144+0%0Aw+16+336+16+352+0%0Aw+16+352+192+352+0%0Aw+192+352+192+272+0%0Aw+256+208+400+208+0%0Aw+400+304+400+352+0%0Aw+400+352+192+352+0%0Aw+400+432+400+464+0%0Aw+400+464+96+464+0%0Aw+96+464+96+208+0%0Aw+96+208+128+208+0%0Ar+624+208+624+464+0+10%0Ad+128+208+192+272+2+default%0Ad+192+272+256+208+2+default%0Ad+192+144+256+208+2+default%0At+544+240+544+208+1+1+-14.911177145175344+0.8210887654686729+10000%0A34+33v-zener+0+1.7143528192810002e-7+0+2+62%0Az+544+352+544+304+2+33v-zener%0Aw+560+208+624+208+0%0Aw+400+208+464+208+0%0Aw+464+208+528+208+0%0Aw+400+464+544+464+0%0Aw+544+464+624+464+0%0Ax+668+349+713+352+4+24+load%0Aw+544+352+544+464+0%0Aw+464+240+464+208+0%0Ar+464+240+464+304+0+1000%0Aw+544+304+544+240+0%0Aw+464+304+544+304+0%0Ao+17+64+0+4099+80+6.4+0+2+17+3%0Ao+0+64+0+

4099+80+102.4+1+2+0+3%0A

ding on settings on the RD6006.

Indeed! What would you suggest that's more elegant? Bonus points for low-co st ;)

-Dan.

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W

1) Become a design engineer, create a 400-watt buck converter, using LTC3895, LTC3703, LTC3810, etc. Or, 2) Purchase the suggested 60V 400W power supply, $33.

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Thanks, - Win
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W

There's an alternate to (1): Instead of a common buck converter, use a DC transformer, or Bus Converter. It's similar, but works at a fixed duty cycle, and has no control loop (the output/input ratio is set by your chosen duty cycle). Therefore it uses a dramatically more simple circuit. Here's our x-Chapter writeup.

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If you're confidant the load won't ever draw excess current, you can eliminate the CS circuitry. Our example was meant for use up to 50V, so it uses 63V caps and 55V MOSFETs. You can use 100V caps and FET, like a CSD19533KCS or an IRFB4310Z. You'll also need to change the LM317 to an LR12, or add a series zener to the circuit.

Thanks, - Win
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W

Better MOSFET choices: FDP085N10A or STP80N10F7.

Thanks, - Win
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D

Thanks Win! At this point I'm favoring options that help me learn about electronics. I'll take a look at the DC transformer. Regards, Dan.

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T

haven't seen too many of those in my lifetime

NT

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