univolt

[frederic.c01]

hi all
my univolt provide 10.71 volts to the as without battery when connect on 110/120 v.
i need 12.5/13.5 volts to charge battery and for 12 v appliances.
what is necessary to change.?

can i power the univolt without battery.?

[Rick Alston]

Yes, the univolt will provide power to 12v lighting without a battery being connected.

I think you have an old univolt that is tired and has lost its ability to charge a battery at the required voltage of 12.5 or greater. A new univolt type unit is needed.

Rick

[john hd]

try the univolt with a battery connected before you junk it.

it is a ferroresonate charger, it needs the battery in the circuit to operate and regulate the voltage properly.

however, 10 volts is a little low for open circuit voltage. rick is most likely right that it is way past it's prime!

it can be repaired by replacing the capacitors in it, be prepared to pay more for them than the cost of a new unit. you can install a new charger and save the fuse panel front, this will allow all of your gauges to work properly. there are a couple of threads that cover this type of conversion.

john

ps. is your voltmeter is reasonably accurate? have you checked it on a known source or against another meter?

[AirConditioner]

I recently replaced my three capacitors with exact (characteristic) replacements from YORK Capacitor. They cost total of about $30.00 with shipping. Ask for Pete (he's on the forum) 802-655-2550 "4 microfarad 660 volt 1.25" oval metal cans." These are commonly referred to as "motor rum" capacitors, and I was also able to get a back-up supply source from a local motor/AC motor repari shop. My unloaded voltage (Univolt humming with nothing connected except an electronic volt/ohm meter) was 24 volts. A small 12vdc lamp connect brought this reading to about 12.8 vdc.

Now if the transformer is bad, I think that might get more expensive than the weight or worth! There are some very fine Univolt replacements out there that have been discussed on the forum.
Dave

[frederic.c01]

hi all
yes it's a old univolt "tu354a" 1972 or1973.
to resolve the problem, I have connect an automatic charger on my two battery.I use the univolt for the 110 volts and the battery for the 12 volts.
it is not easy for the parts I live in France.
fred

[emanon25]

Originally Posted by john hd

try the univolt with a battery connected before you junk it.

it is a ferroresonate charger, it needs the battery in the circuit to operate and regulate the voltage properly.

however, 10 volts is a little low for open circuit voltage. rick is most likely right that it is way past it's prime!

it can be repaired by replacing the capacitors in it, be prepared to pay more for them than the cost of a new unit. you can install a new charger and save the fuse panel front, this will allow all of your gauges to work properly. there are a couple of threads that cover this type of conversion.

john

ps. is your voltmeter is reasonably accurate? have you checked it on a known source or against another meter?

i don't know the circuit on the univolt however, it sounds like one of four diodes in a bridge rectifier has failed. i suspect the only part of a univolt that would be prohibitive to replace would be the stepdown transformer. i've heard on this forum that some univolts use power transistors to regulate charging voltage. these can be replaced as well. i frequently read of univolts that are boiling battery electrolyte. that sounds like a regulator failure (power transistors) too low voltage sounds like a rectifier (diode) has failed.

emanon

[frederic.c01]

hi all
I have find in France a univolt which functions of 110 v to 220 v inpout and 110 /12v output.And which battery charger too for 420 euros or 500 usd.
fred

[JohnG]

If you end up needing to replace it you might want to take a look at this site; http://www.bestconverter.com/ you can get an 80 amp model for only $234.95 and lower amp models down to 30 amps for $154.95
A lot of folks have used these to replace their univolt.

[frederic.c01]

hi johng
thank's for this web site.
price are very interesting .
i think a 30 amp converter is correct for my safari.
what do you think about that?
fred