Construction details of A Complete 13.8 Volt, 50 Amp Power Supply

[johncoles51]

Exactly why I am building this, my DIY switch mode makes a hell of a noise on HF lower bands.!
The now redundant switch mode 30 amp PSU from Amazon made an excellent lead acid battery charger though!

 

[cathead]

Exactly why I am building this, my DIY switch mode makes a hell of a noise on HF lower bands.!
The now redundant switch mode 30 amp PSU from Amazon made an excellent lead acid battery charger though!

I like your thinking! I use a heavy transformered Astron 35 amp supply for powering my radio stuff. I have
several SMPS that may end up as battery chargers or parted out.

 

[johncoles51]

RF noise from switch mode power supplies is my reason for building this, thanks Petros!
I have taken the mains off the PCB and will use a panel mounted relay in place of it. It fits nicely in my case with the large metalclad 50 watt 50 ohm resistor I also used, keeping the 220 volt at the front panel end.

 

[brino]

@johncoles51

Welcome to the group!

-brino

 

[dirty tools]

I got a surplus RV power supply
out put is both ac 110v and 12 v dc

 

[johncoles51]

@johncoles51

Welcome to the group!

-brino

Thanks Brino! I am sorry to say I am only here for the PSU though!

 

[johncoles51]

RF noise from switch mode power supplies is my reason for building this, thanks Petros!
I have taken the mains off the PCB and will use a panel mounted relay in place of it. It fits nicely in my case with the large metalclad 50 watt 50 ohm resistor I also used, keeping the 220 volt at the front panel end.

 

[RJSakowski]

I have built several constant voltage battery charges for recharging my deep cycle marine batteries us stock switching power supplies. The first one used two 5 volt 40 amp Power One supplies with the voltage jacked up to 7 volts by switching the Zener diode. I bought the supplies at hamfests for a couple of dollars each and they served me well for years. The second charger was built with three 5 volt 40 amp MeanWell supplies and the third using two 7.5 volt 40 amp MeanWell supplies. All of these switching supplies were acquired for $5 each or less. Voltage was adjusted to 14.0 volts which os my preferred charging voltage for deep cycle batteries. There is a small series resistance to limit current when charging a dead flat battery.

The supplies are built into metal tool boxes and have external cooling fans as well as digital volt/amp meters. The fans can be switched off to allow use in light rain. Not sure it's IP65 though.

 

[petcnc]

Thanks Brino! I am sorry to say I am only here for the PSU though!

Amazing! I was not expecting that there would be a need for such an old PSU design!
The original design came from radio amateurs, I made it for a car mechanic friend mainly because I had made a transformer capable of giving 50A @ 16V.
I'm happy that so many people find a use for it
petros