I construct a very powerfull and reliable power supply for my laboratory that can give around 10 Ampere from 0-30 volt dc with 6 transistor tip3055 .
Lets see what we have here
in this pdf file you can find ,schema,pcb board,usefull information,all conections and part list
I made an aluminium rectangular box 310mmx200mmx180mm. There is not tte back side because i will place a huge heat sink
here you can see the pcb with 6 power transistor tip3055 (its the same with 2n3055 but in different case)
the main pcb and transistor pcb is ready for placement
transformer is and 2×12 volt 360 watt and yes it is made in GREECE!! You can also use 2×18 volts as described in the manual
If you already read the manual you will notice that you should done some tests using a lamp for making the required adjustments
Second step is 2 usefull meter ,one for measuring volts and the other for amper .You can find those in this section .We made two if those connecting in a differnet way so that measure the voltage and at the same time with the other one measure the amper.
Project is continued with a thermostat.It is a circuit with a thermistor stucked at the heat sink. There are 2 fan at the heat sink that is always working at a low voltage 5 volts.But when the heat sink rise more that 50 degrees Celsius ,the relay of the thermostat close and transistor works at full power 12 volt. One of this blows the air and the other one suck air .
R1 NTC 103 10 KOhm NTC Thermistor
R2 Resistor 4.7 KOhm 1/4 Watt 5% Carbon Film
R3 Resistor 100 KOhm 1/4 Watt 5% Carbon Film
R4 Resistor 5.6 KOhm 1/4 Watt 5% Carbon Film
R5 5 KOhms potentiometer
R6-7 Resistor 2.2 KOhm 1/4 Watt 5% Carbon Film
IC1 LM741 Operational Amplifier
Q1 2N2907 General pnp purpose amplifier and switching transistor
you can see thermistor attached to the heat sink
mow I place everything inside
those 3 resistors are shunt resistors
you can see heat sink here. It is a big piece of aluminium place 2 fans and electrolytic capacitors and the bridge
transistors are places inside the aluminium box. Those fans are off,but when thermostat reach 50 Celsius or more, both fan blow air inside.
Upper fans ,as told before works at 5v. When heat sink reach 50 celsious or more ,then works at 12 v
Hello man, good work! I have a question, what about the 3 resistor doing the shunt? I can found this on the PDF
Hi friend thanks ,those are R1-R6 on TRANSISTOR PASS BOARD. It is 0.22 Ωhm 5 w
Thanks for your fast reply!
Another question, You say “transformer is and 2×12 volt 360 watt and yes it is made in GREECE!! You can also use 2×18 volts as described in the manual”.
I cant found in the PDF the detail of 2x18Volts, its only sats 2x15V, I need change a component value to use the 2x18V?
Hi. Very nice of you to share the complete power supply project. I want to make one. Can you please e-mail me soft copy of only the PCB’s used. I will prepare and etch them in Ferric cloride solution. Please email me at email@example.com. Thanks and Regards – Emilio DSouza Its for my personal use
Hi friend, i don’t jhave gerber files for this, i have the pdf file here
You will go to page 4 and print that page and you’ll continue with Ferric cloride solution ….
Yes , that’s right ,it is 2×15 in the manual and not 2×18 .You will not have any problem with 2×18 , you don’t need to change anything it is a very small difference and capacitor can handle it, you will also have around 34 Volt maximun output voltage ,go on.
A last question man, can I use an shunt like the picture https://sc01.alicdn.com/kf/HTB125DVKFXXXXaSXXXXq6xXFXXXu/100A-75mV-DC-Current-Shunt-For-Ammeter.jpg in replacement of the SHUNT RESISTORS (3x 10W .68 ohms)? Thanks
Hello man, I have leaved a question but was deleted. Im working in this power supply and I need to know if I can replace the resistors of the SHUNT (3x 68J 10W) at the output using a metallic DC shunt with 70A support.
thanks for your reply!
Hi friend ,yes of course you can but it is over kill, 70A is too much ,even those at 10W are not hot almost at all
Thanks a lot your work is great, I already have an 70A DC shunt from an LCD volt-amp display then I want to use it to avoid spend more money.
I see in your last picture a short circuit to test max Amp, this circuit has short circuit protection or I will burn the power supply? The output voltaje is stable under high loads?
Yes of course it has a short circuit protection but with potensiometer for current limiting not at full range for a long time