Episode 713 Back to basics: Power Supply Voltage regulation and pass transistor, heat sink considerations Product: www.banggood.c... Manual: www.icstation.c... Be a Patron: / imsaiguy
Hint for “young players”: toss a 2nd pass element configured as a follower between the rectifier and the storage capacitor. Since AC isn’t on all the time, you get up to 35% power dissipation reduction for almost no effort, and the “final”’regulator stage can operate with very low dropout voltage.
Great explanation sir . Iam also building a power supply ( 30V ,1 A ) I have a transformer with 0 ,15 and 30 V taps .now the problem is when I change the taps with relay, say 15 V tap to 30 V tap the the filter cap (3500uf) creates sparks at relay . I have searched a lot about snubber for this configuration but nothing works . Can you please help ? With a video or a schematic to learn this tap changing technique.
Here is a schematic of a supply with relay switching. elektrotanya.com/mastech_hy-1803d_single-output-dc-power-supply_sch.pdf/download.html you could try a surge protector: www.mouser.com/ProductDetail/Littelfuse/ST1R020B/?qs=gGwQ3tp6HcQeByB84iAXFw%3D%3D or resistor. I would guess a spark is normal and the relay must be good enough to handle this.
@@IMSAIGuy Yes, I watched it. Great video by the way! On part 2 you say that the OPAMPs are supplied at -5V/+30V. This means that the output of this circuit will always be smaller than 30V. Even if the OPAMPs are rail to rail you are losing at least 1 volt from the Darlington pair. Am I missing something?
The power supply course is exactly what many of us needs to learn. Thank you so much for educating us.
good to hear
This is by far the best electronics teaching I found so far on youtube.
These are so lucid. Thanks for this. A lot of things are all getting pulled together in my mind
Glad you like them!
This is a wonderful series of videos. Thank you!
Glad you like them!
I like when you explain the use of relays on linear PSU to optimize efficiency and reduce the heat sink size ! Very clearful. Great !
Hint for “young players”: toss a 2nd pass element configured as a follower between the rectifier and the storage capacitor. Since AC isn’t on all the time, you get up to 35% power dissipation reduction for almost no effort, and the “final”’regulator stage can operate with very low dropout voltage.
Brilliant! Thanks.
If your power supply has a selector switch which selects a relay which then selects a coil tap, why can't the switch itself select the coil tap?
there is a manual switch in many supplies. Usually two ranges.
Great explanation sir .
Iam also building a power supply ( 30V ,1 A ) I have a transformer with 0 ,15 and 30 V taps .now the problem is when I change the taps with relay, say 15 V tap to 30 V tap the the filter cap (3500uf) creates sparks at relay . I have searched a lot about snubber for this configuration but nothing works .
Can you please help ?
With a video or a schematic to learn this tap changing technique.
Here is a schematic of a supply with relay switching. elektrotanya.com/mastech_hy-1803d_single-output-dc-power-supply_sch.pdf/download.html
you could try a surge protector: www.mouser.com/ProductDetail/Littelfuse/ST1R020B/?qs=gGwQ3tp6HcQeByB84iAXFw%3D%3D
or resistor.
I would guess a spark is normal and the relay must be good enough to handle this.
I looked at my HP E3631A supply and it uses triacs bta06-600b
could you use a fairly large Heat sink and Thermo-electric Cooler plate at 12v 100watts?
or something similar?
In place of a noisy fan?
sure, many of the old HP power supplies had a very large cast aluminum heat sink
like this one: ruclips.net/video/300NSoyKDS4/видео.html
+V has to be greater than 30V if we want the output to reach 30V. Where do you get that +V from?
it is generated by a bridge rectifier from a transformer, didn't you watch part 1?
@@IMSAIGuy Yes, I watched it. Great video by the way! On part 2 you say that the OPAMPs are supplied at -5V/+30V. This means that the output of this circuit will always be smaller than 30V. Even if the OPAMPs are rail to rail you are losing at least 1 volt from the Darlington pair. Am I missing something?
@@andel0792 sure, if you needed 30V then the supply will need to be a volt or two more
@@IMSAIGuy And why do we need the -5V?
@@andel0792 so it can operate at zero volts well
What is the role of C4?
low pass, smoothing
Another "bead". Thanks.