I'm not sure it gets more gutless than this

[evilkitty]

When my dad asked me to 'fix' his battery maintainer he knew they were fix able cause someone 'fixed' his old one a long time ago, well here i am holding this 'old' one, it belongs in a museum, i assume what few parts are quality ones cause this was from the days when people used quality stuff, i guess quality and design are very different things

This think has absolutely no regulation

I found 2 diodes in the bottom of the box just laying there
This thing appears to have 3 components
1 diode (assuming 1 is the old one, or the guy just dropped one and did not bother to remove it)
1 light bulb thingy, looks to be a thermal disconnect to prevent a burning out the transformer
1 transformer (rated at 3 amp)

the diode has this on it
1N
4001
I R
forward voltage is 0.5v

[eccerr0r]

Re: I'm not sure it gets more gutless than this

That's all they could do without (cheap) op amps back then...

[kaboom]

Re: I'm not sure it gets more gutless than this

Typical of its time. Transformer, diodes, and thermal breaker. Nicer ones had an ammeter too.
Usually, you'd put in bigger diodes, like 1N5401s or 6A10s (3A & 6A respectively), and non-crumbly AC and battery cables. Possibly battery clamps too.

A common trouble point is that voltage selector switch. Just permanently wire it for 12V out.

[budm]

Re: I'm not sure it gets more gutless than this

Just a simple 60Hz (half wave) or 120Hz (full wave, depends on how those two diodes are connected to the transformer winding) pulse charging.

[evilkitty]

Re: I'm not sure it gets more gutless than this

by drawing skill are lousy but this is how the circuit looks to me
i am assuming a diode goes between the disconnect and 0v
i am assuming the one that was there melted the solder and fell out or the soldering was crappy

[sam_sam_sam]

Re: I'm not sure it gets more gutless than this

Where is your diode or diodes in this drawing ( or a bridge rectifier )

This is a not a requirement but it might work more efficiently if you put a 47000uf @35 volt cap in it with a bridge rectifier

Then you would have a one amp power supply that is filtered so use as a batteries charger or a power supply you could also put a switch on the cap if you did not want it filtering the power supply all the time

[redwire]

Re: I'm not sure it gets more gutless than this

I see a Radio Shack power transformer 12.6VCT and a glass thermal circuit breaker, missing two half-wave rectifiers.

I made something like this and the output voltage was all over the place, it usually dried out the battery.
I would stick a LM317 and heatsink, 1A is more than enough for a float charger.

[eccerr0r]

Re: I'm not sure it gets more gutless than this

The question is what do you want to do with it, if you just want to restore this back to how it was originally, you only need to insert the diode back in, cathode to the "0v" node and anode to the thermal break.

Chances are, someone was working on this before and abandoned it for whatever reason, IMHO.

[Relayer]

Re: I'm not sure it gets more gutless than this

Hello evilkitty,
You could try the circuit shown below:



If you want to keep it original though, then follow
eccerr0r's suggestion.
Regards,
Relayer

[evilkitty]

Re: I'm not sure it gets more gutless than this

Where is your diode or diodes in this drawing ( or a bridge rectifier )

This is a not a requirement but it might work more efficiently if you put a 47000uf @35 volt cap in it with a bridge rectifier

Then you would have a one amp power supply that is filtered so use as a batteries charger or a power supply you could also put a switch on the cap if you did not want it filtering the power supply all the time

The diode is missing in the circuit cause it is missing in the unit, i drew what i saw, not what what i think it should be
notice the black wire at the top of the unit has nothing on it
i was just gonna restore to original 'working' order, my dad has so much of this shit, it is not worth the effort
i have 6 units (varying model #s) to look at next to me and he bought another today, at least that one has a 5 year warranty, which is respectable by PC PSU standards

@Relayer
What software or website did you use toe make that image?
while i did consider making it better, i really do not have interest in doing so

[Relayer]

Re: I'm not sure it gets more gutless than this

Hello evilkitty,

What software or website did you use toe make that image?

I originally drew it using my Eagle schematic proggie.
I then did a screen capture and opened it using Corel 7.
I removed any unwanted values, arrows and location marks.
I then converted it to 8-bit greyscale.
I used Micro$oft Photo Premium 10 to place the watermark.

while i did consider making it better, i really do not have interest in doing so

Pity. Since its so old, it would be considered a vintage item, and perhaps worth a few dollars to a collector.
Regards,
Relayer

[budm]

Re: I'm not sure it gets more gutless than this

Hello evilkitty,
You could try the circuit shown below:



If you want to keep it original though, then follow
eccerr0r's suggestion.
Regards,
Relayer

Why do you have D2 in the circuit for? It is half-wave so only one diode is needed.
BYW, the output will not be 12V due to the cap will be charged up to the peak of the AC Voltage, it will be higher than 12V.

[evilkitty]

Re: I'm not sure it gets more gutless than this

AC output looks to be 13.8v
but there are 2 diodes in the circuit so the total Fv would be about 2v
we would have 11.8v after that v drop

[budm]

Re: I'm not sure it gets more gutless than this

AC output looks to be 13.8v
but there are 2 diodes in the circuit so the total Fv would be about 2v
we would have 11.8v after that v drop

What are the AC Voltage between 0V pin of the transformer and the 6V pin of the transformer, same for the OV pin and the 12V pin of the transformer?
Did you actually fins out how the two diodes are connected in the circuit?
Do not forget the Voltage you are reading is not pure DC due to no filter cap in the circuit. You meter is trying to measure pulsing DC.
Look up rectifier circuit to know what the output wave form will look like without filter cap and how to calculate what the DC Voltage will be.
http://www.electronics-tutorials.ws/diode/diode_5.html

[Relayer]

Re: I'm not sure it gets more gutless than this

Hello budm,

Why do you have D2 in the circuit for? It is half-wave so only one diode is needed.

Could you please tell me the detrimental effects if two diodes were in circuit rather than one?

BYW, the output will not be 12V due to the cap will be charged up to the peak of the AC Voltage, it will be higher than 12V.

I realize this, and yet it originally had one diode and no filtering what so ever. Ripple would have been relatively high with half wave rectification.
So what should I have labeled the output voltage. 13.4, 16V with ripple???
Regards,
Relayer

Edit:
@ evilkitty
The more I look at that thermal disconnect, it looks more like a mercury tilt switch.
Is one of the components pigtail attached to the top of the transformer?

[evilkitty]

Re: I'm not sure it gets more gutless than this

Pity. Since its so old, it would be considered a vintage item, and perhaps worth a few dollars to a collector.
Regards,
Relayer

If we are going for vintage wouldn't original working order be better? as opposed to adding a pcb with a few components in it?
to my understanding it just needs to ~$0.50 diode to be vintage
now if wanted to upgrade this design i could slap a few caps in this thing and rewire it, but then it would not be original in its design, all of the components are on the ground side of the circuit

definitely not a mercury tube, it looks similar to a blinking bulb in a Christmas tree light string, just looks less cheap
it looks to have a spot welded or soldered joint to the top of the transformer
this is a metal brace to a non-conductive material that was made to hold 2 components, looks to have been used to hold wires to they do not move and break the disconnect

[evilkitty]

Re: I'm not sure it gets more gutless than this

What are the AC Voltage between 0V pin of the transformer and the 6V pin of the transformer, same for the OV pin and the 12V pin of the transformer?
Did you actually fins out how the two diodes are connected in the circuit?
Do not forget the Voltage you are reading is not pure DC due to no filter cap in the circuit. You meter is trying to measure pulsing DC.
Look up rectifier circuit to know what the output wave form will look like without filter cap and how to calculate what the DC Voltage will be.
http://www.electronics-tutorials.ws/diode/diode_5.html

i was measuring the transformer's AC output, no diode in circuit
the loose diodes do not have the proper amp rating, i am guessing someone used 2 thinking it would be good for 2a, was that myth believe back in the day?
I did manage to get my dad to tell me the last guy that fixed it told him it was upgraded to 1.5A, so i guess the thermal disconnect broke last time; therefore there is no way to reliable use the 1A diodes

[CapLeaker]

Re: I'm not sure it gets more gutless than this

Hello budm,


Could you please tell me the detrimental effects if two diodes were in circuit rather than one?


I realize this, and yet it originally had one diode and no filtering what so ever. Ripple would have been relatively high with half wave rectification.
So what should I have labeled the output voltage. 13.4, 16V with ripple???
Regards,
Relayer

Edit:
@ evilkitty
The more I look at that thermal disconnect, it looks more like a mercury tilt switch.
Is one of the components pigtail attached to the top of the transformer?

This isn't ripple, that is "pulse charging" and that is what they actually wanted. Lead acid batteries love to be pulse charged they desulfate really well like that. Depending on the voltage of the charger, you may have to unhook the battery from the car. I am pulse charging all my lead acid batteries. You don't find a "smoothing" capacitor on the alternator to charge the car battery either.

[kc8adu]

Re: I'm not sure it gets more gutless than this

i have the exact unit on my bench.
i use it for long term eq/desulphating.
its not a maintainer.it can hit 16v at light load.
iirc mine has selenium rectifiers.

[evilkitty]

Re: I'm not sure it gets more gutless than this

it looks like 2 of the units he gave we were chargers, one has a bad switch, rewired it to only be 12v