Comments on: 13.8 Volt 20 A Transformerless Power Supply

By: Opanin17

Opanin17 — Sun, 16 Oct 2016 21:32:10 +0000

â€‹Thanks for your nice idea. I saw a circuit in this post that can charge any battery size.

http://helpersalone.blogspot.com/2016/10/inverter-…

can you please advice me?

By: Anindya

Anindya — Mon, 17 Oct 2011 13:08:16 +0000

Plaese let me know what is the input current value/range of this circuit so that it will give 20amp o/p current…
Input voltage value already mentioned in heading but not input current…

By: circuit diagram

circuit diagram — Thu, 26 May 2011 05:33:53 +0000

In reply to Pol-P. i've check the PCB. C3 on PCB layout should be C4 on the diagram. While C2 on PCB layout should be C3 on the diagram. You need to add C2 on the PCB layout by yourself (refer to the diagram). C1 is a ordinary electrolytic capacitor (ELCO). Based on the PCB, the will 3x elco of paralled 13300uF / 33-63V. The RL will be 10 x 0.3 ohm resistor with parallel connection. It will resulting 0.03 ohm right..?

By: Pol-P

Pol-P — Wed, 25 May 2011 12:12:34 +0000

I’m trying to locate the position of C4 in the PCB but unfortunately it’s not included, where is it? What is the exact value of C1? Is it ceramic, tantalum, or if it’s electrolytic, what is the voltage required? What is the exact value of RL? very confusing, (0,03R and 0R3) what is that value?

By: Ryan B.

Ryan B. — Wed, 27 Apr 2011 07:39:03 +0000

If this is transformerless, why do we need a 25a 17.5v transformer? If we have a 25a available for the required input, we don’t need this circuit, since it’s only 20a at the output.

By: ryan B.

ryan B. — Wed, 27 Apr 2011 07:31:07 +0000

If this is transformerless why do we have to use 25A 17.5v transformer? If you use 25A input power naturally the output would be parallel. It means we don’t need this circuit, since we have already 25A power available at the input.

By: jayddep gajipara

jayddep gajipara — Mon, 18 Oct 2010 12:29:29 +0000

hi sir
sir i request u that we want to say how to convert three phase to single phase 30 mA power supply from three phase without neutral and transformer plz give me idea for 440 volt without occurring fault

By: jomish k j

jomish k j — Mon, 21 Jun 2010 13:03:41 +0000

Hai, thank you for your circuit,but one thing that without a transformer it can not be used in india.Why because i have a power supply of 230v and 430v.

By: satya

satya — Sun, 28 Mar 2010 07:32:28 +0000

This circuit is not a transformerless circuit diagram.
But this is regulater for 19 v transformer .I just want to say if you can provide a smps circuit diagrame than that would be helpfull instead of this.

By: Francesco

Francesco — Thu, 29 Oct 2009 23:54:36 +0000

Hi,
just a comment: this circuit is transformerless in the sense that it doesn’t clearly shows the transformer symbol but you will still need a “very-very expensive, large in size and very heavy in weight” transformer to derive the 19.5 DC volts 20A supply that is the input of this circuit…