Ajustable Power Supply

[nelioabreu]

Hi there,

I'm looking for a schematic of an ajustable power supply, for both voltage and amper, from 0 to 45V and 0 to 10A, with digital voltmeter and digital ampermeter.

Does any one have anything like it out there?

Thanks in advance.

 

[picbits]

Try doing a search on adjustable power supply

 

[andy257]

There are lots of variable power supply designs floating around on the net. Just do a search on google. I have not come accross any with your exact spec.

Just to make you aware a 10A supply at 45V is going to be one huge supply, assuming its a linear power supply you are requiring. That is one huge transformer you will need. Your supply is going to be very heavy.

What do you plan on using this supply for?

 

[Willbe]

Hi there,

I'm looking for a schematic of an ajustable power supply, for both voltage and amper, from 0 to 45V and 0 to 10A, with digital voltmeter and digital ampermeter.

Does any one have anything like it out there?

Thanks in advance.

Making DC

A 10 A diode is series with 120 vRMS will give you a DC voltage of ~50v. The diode will dissipate 17 W 'cause the RMS value of the current waveform through the diode is higher than 10 A, so you'd need a diode heatsink, maybe with a fan.
The peak voltage is 170v so the downstream capacitors need a V rating of ~350 v [big $$$] unless you don't need filtered DC.

The 600 W transformer for this may cost you $50, and if you want 45 v at the same time you want 10 A, that is, a 450 W output, you'll need a lot of heatsinks or a large Variac.
If you can get specials on smaller xformers, etc., you can parallel them.

If you have four car batteries that you can switch in and out, you can save on the xformer and the huge capacitors and some of the heat sinks, and still get reasonable operating time.

Or you could use a vehicle alternator run by a 1 hp motor [possibly an electric drill]. The diode bridge inside the alt would probably need to be replaced with diodes that can stand the PRV while delivering 45 vdc.


Regulation/filtering

For regulated and filtered voltages National Semiconductor has application notes on how to extend the range of their IC regulators to handle this input voltage and output current. To get voltage regulation down to zero volts you'll probably need a low-current negative supply.

I can't find my paper copy of these notes, but they might already have an entire schematic for this kind of power level.

This sucker is $1400
https://www.bkprecision.com/www/power+supply2.asp
so that is the cost of the parts, and assembly and test time at probably $10/hr.

Misc.

You could also build the raw DC supply and then have various sizes of regulators [1 A, 3 A] and mix and match depending on your need.
Very flexible.

And, for extra voltage/current, you can series/parallel a car battery or batteries with your supply.
Don't forget, if your load resistance doesn't vary you can have 9 A of unregulated current fed into a load, and it's only the last 1 A that is regulated. This takes the burden off the regulator.

 

[mneary]

If you follow the instructions in the post above, make sure your affairs are in order. Be afraid.

 

[Willbe]

If you follow the instructions in the post above, make sure your affairs are in order. Be afraid.

For $1400 you never have to be exposed to voltages over 60 vdc.

If you build line powered or car battery powered supplies and your life is worth what value the U. S. car companies place on a human life [200 kilobucks] then you should buy the supply if you judge the likelihood over the rest of your life of you getting zapped with these homebrew gadgets to be > 1.4/200 = >1 chance in ~140.

To put this in perspective, the chance of a 60 year old non-smoking male in the U.S. dying from any cause within the next year is 1/50.
Where's my soldering iron???

 

[jpanhalt]

Here is a link to a 0-20V, 4A supply with digital readout. Click on "bench supply." It may give you some ideas. John

 

[kchriste]

A link to a 60V 50A power supply:
http://www.home.agilent.com/agilent...384-1:epsg:man&lc=eng&cc=US&nfr=-35687.384731
Or you could just buy it. It's only $5500US assembled and tested.

 

[Willbe]

1.5 A, up to 57 v, and you'll need 7 ea.
**broken link removed**
plus you'll need a -1.2 v supply at low current and heatsinks for the regulators.

The regulator price is $1 in qty of 1000 from National Semi so see what these guys want for them
http://www.4starelectronics.com/part_detail/lm317hv.html?master=3212628

If you don't use four car batteries, the filter cap upstream of the regulators needs a C equal to I*ΔT/ΔV; with I = 10 A, ΔT = 8 mS, ΔV = 5 V then C = 16,000 µF @ 75 V. (Hosfelt pn 15-1037, 16 ea. @ $0.75 ea. or equivalent)
and a heatsink for the full wave diode bridge.

You still need to scare up a 2:1, 120 v:60 v 10 A, 600 w transformer.
Junked battery chargers?
Microwave oven xformers with 120 v fed into the paralleled HV outputs and 60 v picked off of the series'ed 120 v inputs, 2 ea.?
A 240:120 isolation xformer running on 120 v input?

This thing is almost assembling itself.

 

[jfedison]

Hi,

Here is a schematic for a general purpose dc power supply that is adjustable from 1.2V to 27V, up to 0.5A. The circuit is based on the LM317.

Changing the LM317 to a LM317HV and a higher voltage output capacitor (C2) would extend the voltage range up to 60V. This circuit is good to 1.5A with the proper heatsink. For higher current, a different design will be needed.

Also, current and voltage readouts could be added using pre-assembled digital panel meters.

Best regards,

Jeff Fedison
---------------------------------------------
Micro Circuit Labs ~ Innovative electronic kits
**broken link removed**

 

[flat5]

"A link to a 60V 50A power supply...only $5500US assembled and tested."

That manual has everything but a picture of the supply

 

[Hero999]

Hi,

Here is a schematic for a general purpose dc power supply that is adjustable from 1.2V to 27V, up to 0.5A. The circuit is based on the LM317.

Changing the LM317 to a LM317HV and a higher voltage output capacitor (C2) would extend the voltage range up to 60V. This circuit is good to 1.5A with the proper heatsink. For higher current, a different design will be needed.

Also, current and voltage readouts could be added using pre-assembled digital panel meters.

Best regards,

Jeff Fedison
---------------------------------------------
Micro Circuit Labs ~ Innovative electronic kits
**broken link removed**

jfedison,
Because R1 is 240R the minimum load current will be 5mA, for a minimum load current of 0mA use 120 and halve the value of R2 to R5, nearest 1% values are 357, 7320, 1020 and 2.5k for the pot.

 

[chemelec]

Using Appropriate Power Transistors/Heatsinks, this supply can supply almost any voltage at any Current.
Although This MC1466 IC is Discontinued, This Circuit Duplicates it very well.

**broken link removed**