Lead acid battery trickle charger questions

R

Rubicon

Guest
Hello,

My uncle bought a little charger from a garage sale and it doesn't
appear to work so passed it on to me to have a look at.

Lead acid battery trickle charger 12/6V 1.2Amp max, 0.5Amp mean.

The mains transformer has three output wires for 12V and 6V. The wire
goes to a, AC~ lead of a bridge rectifier, the second and third to the
outer terminals of a SPDT rocker switch for 12 or 6V. The common
terminal is connected to the second AC~ lead on the bridge rectifier.
A DC lead of the rectifier goes to the + terminal of the car battery.
The batteries negative terminal connects to a thermal switch which
connects to the (the part I don't understand) positive "Charging" LED
lead via its 330Ohm/1Watt resistor and then goes back to the second
rectifier DC lead. The resistor is so badly burnt I had to measure it
but there's also a broken bare wire on the LEDs negative lead and
another on the thermal switches terminal to the resistor. It's like
fusewire and as if they were joined but if joined they cut the LED and
resistor out of the circuit. I don't know what it's there for. Any
ideas on what its function is?

Perhaps I can't see the woods for the trees here.

Cheers,

Andrew.

Remove the ZZ from E-Mail address to contact me.
 
Rubicon wrote:
Hello,

My uncle bought a little charger from a garage sale and it doesn't
appear to work so passed it on to me to have a look at.

Lead acid battery trickle charger 12/6V 1.2Amp max, 0.5Amp mean.

The mains transformer has three output wires for 12V and 6V. The wire
goes to a, AC~ lead of a bridge rectifier, the second and third to the
outer terminals of a SPDT rocker switch for 12 or 6V. The common
terminal is connected to the second AC~ lead on the bridge rectifier.
A DC lead of the rectifier goes to the + terminal of the car battery.
The batteries negative terminal connects to a thermal switch which
connects to the (the part I don't understand) positive "Charging" LED
lead via its 330Ohm/1Watt resistor and then goes back to the second
rectifier DC lead. The resistor is so badly burnt I had to measure it
but there's also a broken bare wire on the LEDs negative lead and
another on the thermal switches terminal to the resistor. It's like
fusewire and as if they were joined but if joined they cut the LED and
resistor out of the circuit. I don't know what it's there for. Any
ideas on what its function is?

Perhaps I can't see the woods for the trees here.

Cheers,

Andrew.

Remove the ZZ from E-Mail address to contact me.
Click to expand...
Try news:sci.electronics.repair

--
We now return you to our normally scheduled programming.

Take a look at this little cutie! ;-)
http://home.earthlink.net/~mike.terrell/photos.html

Michael A. Terrell
Central Florida
 
"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:4002C812.89C0419B@earthlink.net...
Rubicon wrote:

Hello,

My uncle bought a little charger from a garage sale and it doesn't
appear to work so passed it on to me to have a look at.

Lead acid battery trickle charger 12/6V 1.2Amp max, 0.5Amp mean.

The mains transformer has three output wires for 12V and 6V. The wire
goes to a, AC~ lead of a bridge rectifier, the second and third to the
outer terminals of a SPDT rocker switch for 12 or 6V. The common
terminal is connected to the second AC~ lead on the bridge rectifier.
A DC lead of the rectifier goes to the + terminal of the car battery.
The batteries negative terminal connects to a thermal switch which
connects to the (the part I don't understand) positive "Charging" LED
lead via its 330Ohm/1Watt resistor and then goes back to the second
rectifier DC lead. The resistor is so badly burnt I had to measure it
but there's also a broken bare wire on the LEDs negative lead and
another on the thermal switches terminal to the resistor. It's like
fusewire and as if they were joined but if joined they cut the LED and
resistor out of the circuit. I don't know what it's there for. Any
ideas on what its function is?

Perhaps I can't see the woods for the trees here.

Cheers,

Andrew.

Remove the ZZ from E-Mail address to contact me.

Try news:sci.electronics.repair

--
We now return you to our normally scheduled programming.

Take a look at this little cutie! ;-)
http://home.earthlink.net/~mike.terrell/photos.html

Michael A. Terrell
Central Florida
Cute dog Mike....do you live in Ocala? Just curious...was thinking about
Click to expand...
relocating from California....
 
Ross Mac wrote:
Cute dog Mike....do you live in Ocala? Just curious...was thinking about
relocating from California....
Click to expand...
About five miles south of Ocala.

--
We now return you to our normally scheduled programming.

Take a look at this little cutie! ;-)
http://home.earthlink.net/~mike.terrell/photos.html

Michael A. Terrell
Central Florida
 
"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:40036A9E.425808F9@earthlink.net...
Ross Mac wrote:

Cute dog Mike....do you live in Ocala? Just curious...was thinking about
relocating from California....

About five miles south of Ocala.

--
We now return you to our normally scheduled programming.

Take a look at this little cutie! ;-)
http://home.earthlink.net/~mike.terrell/photos.html

Michael A. Terrell
Central Florida
Click to expand...
Any suggestions on towns around the Ocala area...perhaps waterfront
property?...Thanks in advance, Ross
 
Ross Mac wrote:
Any suggestions on towns around the Ocala area...perhaps waterfront
property?...Thanks in advance, Ross
Click to expand...
There aren't many towns in Central Florida without waterfront
property. I would suggest you make a visit to the area, and visit
different towns to find what you are looking for. The Ocala area, and
several nearby places are full of retirees, golf courses and such. Other
areas of Florida are better for finding jobs. Ocala is full of itself
over their horse farms. If you want a place with lots of water, take a
look at lake county, just south of Ocala, but be warned, the soil is
mostly sand from there, south.

--
We now return you to our normally scheduled programming.

Take a look at this little cutie! ;-)
http://home.earthlink.net/~mike.terrell/photos.html

Michael A. Terrell
Central Florida
 
"Michael A. Terrell" <mike.terrell@earthlink.net> wrote in message
news:400465D1.CE2FA3B8@earthlink.net...
Ross Mac wrote:

Any suggestions on towns around the Ocala area...perhaps waterfront
property?...Thanks in advance, Ross

There aren't many towns in Central Florida without waterfront
property. I would suggest you make a visit to the area, and visit
different towns to find what you are looking for. The Ocala area, and
several nearby places are full of retirees, golf courses and such. Other
areas of Florida are better for finding jobs. Ocala is full of itself
over their horse farms. If you want a place with lots of water, take a
look at lake county, just south of Ocala, but be warned, the soil is
mostly sand from there, south.

--
We now return you to our normally scheduled programming.

Take a look at this little cutie! ;-)
http://home.earthlink.net/~mike.terrell/photos.html

Michael A. Terrell
Central Florida
Thanks Mike.....I was just looking for an inside look...I am headed there
Click to expand...
next month...take care, Ross
 
Ross Mac wrote:
Thanks Mike.....I was just looking for an inside look...I am headed there
next month...take care, Ross
Click to expand...
If you are going to be in the Ocala area E-mail me and I'll give you my
phone number.

--
We now return you to our normally scheduled programming.

Take a look at this little cutie! ;-)
http://home.earthlink.net/~mike.terrell/photos.html

Michael A. Terrell
Central Florida
 
Andrew,

If you're gonna fix it, exercise caution around the 120 volt
connections and transformer primary wiring!

The resistor and LED are there to indicate there is output
voltage and the thermal switch has not tripped. Purchase
any regular flavored LED as replacement and use ohms law to
compute your series resistor (ask at radio shack or use
their 12 volt version that has a resistor already
installed).

To fix the unit, first check the output of the transformer,
then input to the AC~ leads of the bridge rectifier in 6 and
12 positions for AC voltage. If present check for DC
voltage between the + and - of same. If both are ok and
there is no output at the clips, short the thermal switch to
check if that's the problem.

If you don't have a meter, use at 12 volt test lamp for AC,
with a diode for DC (presence is more important than
polarity as long as the output red clip routes to the +
terminal of the bridge rectifier).

If replacing the LED, have + of bridge route to the anode
lead, - to cathode lead, either through appropriate
resistor. A regular red diffused LED will set you back
about a dime, and can use a 680 ohm 1/2 watt resistor (1
watt is better if it's near anything generating heat) - but
you can also just forget these [parts if you feel like it
and check output with any 12 volt lamp if you hear the
thermal cutout clicking...

Good luck and remember not to touch the 120V wiring (it
HURTS <s>).

By the way, a transformer can be had at most surplus or
electronic stores for 2 1/2 to 10 bucks, the bridge
rectifier for a buck or two, and the thermal cutout may be a
mail catalog item. These come in handy to throw under the
hood, so if it were me, I'd rather fix it than scrap it.

Good luck!

Rubicon wrote:
Hello,

My uncle bought a little charger from a garage sale and it doesn't
appear to work so passed it on to me to have a look at.

Lead acid battery trickle charger 12/6V 1.2Amp max, 0.5Amp mean.

The mains transformer has three output wires for 12V and 6V. The wire
goes to a, AC~ lead of a bridge rectifier, the second and third to the
outer terminals of a SPDT rocker switch for 12 or 6V. The common
terminal is connected to the second AC~ lead on the bridge rectifier.
A DC lead of the rectifier goes to the + terminal of the car battery.
The batteries negative terminal connects to a thermal switch which
connects to the (the part I don't understand) positive "Charging" LED
lead via its 330Ohm/1Watt resistor and then goes back to the second
rectifier DC lead. The resistor is so badly burnt I had to measure it
but there's also a broken bare wire on the LEDs negative lead and
another on the thermal switches terminal to the resistor. It's like
fusewire and as if they were joined but if joined they cut the LED and
resistor out of the circuit. I don't know what it's there for. Any
ideas on what its function is?

Perhaps I can't see the woods for the trees here.

Cheers,

Andrew.

Remove the ZZ from E-Mail address to contact me.
Click to expand...
 
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