Battery Charger Capacitor

[TwoBlocked]

Have always wondered just how battery chargers that have a transformer coil going to a capacitor work. Like this one for example. One thing I do know is ya gotta have the correct size capacitor. Bigger is not better, unless you like magic smoke. damhik. I think it has something to do with partially saturating the core of the transformer to control the charging current, Can anyone point me in the right direction to understand this type of circuit?

 

[gar]

230609-0625 EDT

TwoBlocked:

That appears to be a ferro resonant approximate constant voltage transformer. In which case you are dealing with a tuned resonant circuit.

.

 

[ptonsparky]

^^What he said.^^



I made my own most simple 24v dc power supply and used a large start capacitor to smooth out the ripples of the full wave rectifier. Worked well enough to fool whatever I was working on that needed DC at the time.

 

[Joethemechanic]

Ive made battery chargers for lead acid batteries using nothing but an incandescent bulb and a diode

 

[drcampbell]

I've made battery chargers for lead acid batteries using nothing but an incandescent bulb and a diode

That sounds safe!

 

[ptonsparky]

That sounds safe!

I was hoping he threw in a transformer some place, but I suppose one could drop the voltage and limit current with one good lamp. May need to try it.

 

[Joethemechanic]

I was hoping he threw in a transformer some place, but I suppose one could drop the voltage and limit current with one good lamp. May need to try it.

You can experiment with different light bulb sizes for different charge rates. This diagram is for neg ground equipment. If you have something positive ground you'll want to flip the diode and the battery. Really best to disconnect the battery before using this charger if you have any doubt or something electronic is involved

 

[Besoeker3]

View attachment 2565694

You can experiment with different light bulb sizes for different charge rates. This diagram is for neg ground equipment. If you have something positive ground you'll want to flip the diode and the battery. Really best to disconnect the battery before using this charger if you have any doubt or something electronic is involved

Not very efficient.

 

[Joethemechanic]

Not very efficient.

Neither is ferroresonant voltage regulation, motor generator chargers, or the chargers with the vacuum tube rectifier, that I had to work with as a kid.

 

[Joethemechanic]

THE AUTOMOBILE​

STORAGE BATTERY​

ITS CARE AND REPAIR​

(Table of) Contents

---

RADIO BATTERIES, FARM LIGHTING BATTERIES​

---

---

A practical book for the repairman. Gives in nontechnical language, the theory, construction, operation, manufacture, maintenance, and repair of the lead-acid battery used on the automobile. Describes at length all subjects which help the repairman build up a successful battery repair business. Also contains sections on radio and farm lighting batteries.

BY​

O. A. WITTE​

Chief Engineer, American Bureau of Engineering, Inc.​

The Automobile Storage Battery: Its Care And Repair

www.gutenberg.org

 

[ptonsparky]

View attachment 2565694

You can experiment with different light bulb sizes for different charge rates. This diagram is for neg ground equipment. If you have something positive ground you'll want to flip the diode and the battery. Really best to disconnect the battery before using this charger if you have any doubt or something electronic is involved

At least I had a full wave rectifier.

 

[Joethemechanic]

At least I had a full wave rectifier.

Yeah I tried that with the light bulb charger. Makes the car's door handles kind of spicy

 

[Besoeker3]

Neither is ferroresonant voltage regulation, motor generator chargers, or the chargers with the vacuum tube rectifier, that I had to work with as a kid.

I disagree but what do I know..........

 

[ptonsparky]

Yeah I tried that with the light bulb charger. Makes the car's door handles kind of spicy

Take it out of the car!!

 

[Joethemechanic]

I disagree but what do I know..........

ferroresonant voltage regulation can be down to like 50% Not sure about the motor generators or the vacuum tubes but from using them both they seem to make a lot of heat.

And how efficient does a trickle charger that you use a couple of days in a year have to be? Nobody cared about efficiency, they just wanted their tractor to start in the spring

 

[Besoeker3]

ferroresonant voltage regulation can be down to like 50% Not sure about the motor generators or the vacuum tubes but from using them both they seem to make a lot of heat.

And how efficient does a trickle charger that you use a couple of days in a year have to be? Nobody cared about efficiency, they just wanted their tractor to start in the spring

We are talking about a battery charger. What is that to do with a motor generator?

 

[Joethemechanic]

Take it out of the car!!

Too much work, especially if it's something like a Model A Ford with the battery under the floorboard

 

[Joethemechanic]

We are talking about a battery charger. What is that to do with a motor generator?

We used to use motor-generators for a dc source for battery charging. Most of them we built ourselves out of generators from junk trucks and drove them with a V belt from an induction motor. Rheostat in the field circuit to control the charging rate.

I still have some similar gasoline powered units around that I use for starting equipment

 

[Besoeker3]

We used to use motor-generators for a dc source for battery charging. Most of them we built ourselves out of generators from junk trucks and drove them with a V belt from an induction motor. Rheostat in the field circuit to control the charging rate.

I still have some similar gasoline powered units around that I use for starting equipment

That's fine but is not related to the original topic.

 

[Joethemechanic]

That's fine but is not related to the original topic.

It's been off topic since the first couple posts. Really that tank circuit ferroresonant voltage regulation is kind of outdated. Although I'd say it's very simple and reliable