what's the voltage loss using this regulator? I am worried about insufficient voltage - I have 15AC in and expect 15VDC @500mA output
15v AC -> 15x1,41 DC -> 21V DC (after rectification) - a lot of headroom to produce 15V regulated DC. Loss is tops a couple of volts...
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Schematic is deleted (entire first post) so i can't sim it to estimate best +Vin for best performance.
I briefly setup a simulation, 20VDC + 1Vrms/120Hz AC as power, keep the output=15v, load current=500mA, change the power DC voltage and watch output ripple, the result:
DC - Ripple
18V - 150mV
18.5V - 40mV
19V - 105uV
19.5V - 56uV
20V - 46uV
Roughly it requre ~5V Vout-Vin , 2N6488 has 2.54W power dissipation. Adding more 10V DC voltage lead to 10uV ripple while 7.5W power dissipation. Seeems AC15in DC15 out is a fair balanced combinaion.
DC - Ripple
18V - 150mV
18.5V - 40mV
19V - 105uV
19.5V - 56uV
20V - 46uV
Roughly it requre ~5V Vout-Vin , 2N6488 has 2.54W power dissipation. Adding more 10V DC voltage lead to 10uV ripple while 7.5W power dissipation. Seeems AC15in DC15 out is a fair balanced combinaion.
I think he deleted them himself, what seems in anger - all #1 posts in every thread.... as these are the only one you can edit after 30 min if you are the OP.
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Thanks @timgrindell
So the BOM for the negative supply would be the same with R14 being 5k6 instead of the 4k7 R8 on the positive supply?
So the BOM for the negative supply would be the same with R14 being 5k6 instead of the 4k7 R8 on the positive supply?
@LongRanger
R14/4K7 for N Reg - R8/5K6 for P Reg
T1/MMBTA92 for P Reg - T3/MMBTA42 for N Reg (0.5A version)
Regards,
Phil
R14/4K7 for N Reg - R8/5K6 for P Reg
T1/MMBTA92 for P Reg - T3/MMBTA42 for N Reg (0.5A version)
Regards,
Phil