I have had one of these chargers for about 25yrs and still going well. Only problem with it is, about 5yrs ago I lent it to my son to charge his battery and he left it on boost all night and nearly melted his battery, and the boost facility has never worked since. I was not very happy with him .The instructions say not to leave it on boost for more than 30 seconds! I have always wondered if it was possible to fix it and now you have given me hope. I will check the diode and see what happens. Thanks for sharing. Paul UK.
According to Frank Zappa, scientists think the hydrogen in the most common element is the universe, but he thinks stupidity is more common on earth. I reckon you will find the rectifier is the problem and if you are lucky, just one diode, cheers
I have fixed lots of battery chargers with bad rectifier diodes by using GM SI, AD and So on Alternator Rectifier Diodes. Just mount the whole positive and negative bridges to heat sink and run all diodes together. With good heat sinking and chargers with cooling fans they do really well and out of All the charges I've fixed with Alt diodes, not a 1 has failed. They also work great in 12vdc power supplies with adidquite heat sinking and cooling. I've built 13.8 VDC Regulated supplies up to 35-40 amps with Alt diodes that ran 80+% duty cycle for HF linear amplifiers and Transmitters.
Hi, yes car alternator rectifiers are great as they are, just using 2 of the 3 inputs. They are designed to be fan cooled but at 20% capacity I agree with you, they are fine, cheers
Very helpful video, I have a Rohr charger /starter which I think I have overloaded, using you help I will try to establish why it is only producing 10V output, what is the best place to get spare parts from.?
Hi, thanks for the message, I have several battery charger repair videos, including one that was crushed. I normally use reclaimed parts were ever possible. It is often difficult to get parts from the manufacturer (and expensive), so search auction sites etc. Hope you have subscribed, cheers
Hi. Are you in a position to tell me the ratings of the diods you have on such start-chargers? I am fixing one of my own... the diods are my unsolved equation. Thanks.
14:50 curious about your reading on DC+ with the clamp meter. I thought those were used on A/c lines? I know there are some available for DC but not commonly available?
Hi, this one has both AC and DCcurrent functions, once you have one you would be lost without it for quick analytics. I hope you enjoy the rest of my video catalogue, Cheers
The diodes in that charger don't look big enough to do much more than a nice charge current - if someone has taken the word 'start' too literally, I am surprised _any_ of the 4 diodes has survived ! The transformer won't do starting current even slightly either .... I know I mentioned this in your last charger repair vid Andy, but I drew the circuit out as you were pointing to bits in this one, and as far as I'm concerned the 12v output is _full wave_ rectified not half - wave rectified, just like the 24v. Though with one failed diode here, both outputs would indeed be only half wave rectified, hence the poor output :o) Have a look at this google image : www.talkingelectronics.com/projects/70InterestingCircuits/images/6v_12vPowerSupply.gif The bottom circuit is what you almost certainly have in your two chargers. Everywhere it says '6v', read that as '12v' , and where it says '12v' read that as '24v' for your chargers. Sorry, short of drawing it out for you myself, I couldn't find a better diagram of what you have on Google ! NB... _both_ outputs are full wave rectified ! Let me know if you need more explanation...... Cheers, Dave
Dave, yes I fully agree with you on the quality of the components, but it's a Clarke and so low end equipment. I suspect Sealy sell the same as it's own . Thanks for the link. I need to discuss this further. From my point of view there is no diode on the centre tap, but having considered your thoughts maybe the negative half of the wave is canelled out by the negative from the rectifier through the battery and so there is no current flow. This just leaves the positive with a path for the current to flow. Cheers, Andy
Clarke stuff is cheap and cheerful I guess ! I will have to give this some more thought Andy - as this dual voltage circuit is a combination of 2 types of rectification - one using 4 diodes in a bridge and the other using 2 diodes and a CT transformer secondary - we need to ignore the 24v output components when looking at the 12v output circuit, or it'll just be confusing... so ignore the two diodes that go to the 24v output, they do nothing at all when considering only the 12v output....ok ? In one sentence - the 12v circuit can be thought of as 2 half wave rectification circuits combined together - each of these consists of one half of transformer secondary, one diode, and the load battery, and because of the way that each half of a CT secondary winding swings +ve and -ve alternately (think of the CT as a pivot point here) each half cycle, and, importantly, _out of phase with each other_ , each of the two half wave rect. loops is active for a different half cycle, so if you then connect these to half wave outputs together, the two waveforms interleave with each other and you get a full wave rectified output - bingo ! I'll email some more tomorrow when I'm more awake.... Dave
I have had one of these chargers for about 25yrs and still going well. Only problem with it is, about 5yrs ago I lent it to my son to charge his battery and he left it on boost all night and nearly melted his battery, and the boost facility has never worked since. I was not very happy with him .The instructions say not to leave it on boost for more than 30 seconds! I have always wondered if it was possible to fix it and now you have given me hope. I will check the diode and see what happens. Thanks for sharing. Paul UK.
According to Frank Zappa, scientists think the hydrogen in the most common element is the universe, but he thinks stupidity is more common on earth. I reckon you will find the rectifier is the problem and if you are lucky, just one diode, cheers
@@TheInfoworks thanks for that, I'll have a look and hope for the best.
Thank you Andy. Very enlightening. Put across in a straightforward, no nonsense way. Good video.
Les Laidler but
I have fixed lots of battery chargers with bad rectifier diodes by using GM SI, AD and So on Alternator Rectifier Diodes. Just mount the whole positive and negative bridges to heat sink and run all diodes together. With good heat sinking and chargers with cooling fans they do really well and out of All the charges I've fixed with Alt diodes, not a 1 has failed. They also work great in 12vdc power supplies with adidquite heat sinking and cooling. I've built 13.8 VDC Regulated supplies up to 35-40 amps with Alt diodes that ran 80+% duty cycle for HF linear amplifiers and Transmitters.
Hi, yes car alternator rectifiers are great as they are, just using 2 of the 3 inputs. They are designed to be fan cooled but at 20% capacity I agree with you, they are fine, cheers
Good video Andy, that charger will survive us !
Very helpful video, I have a Rohr charger /starter which I think I have overloaded, using you help I will try to establish why it is only producing 10V output, what is the best place to get spare parts from.?
Hi, thanks for the message, I have several battery charger repair videos, including one that was crushed. I normally use reclaimed parts were ever possible. It is often difficult to get parts from the manufacturer (and expensive), so search auction sites etc. Hope you have subscribed, cheers
Dear sir can i use Gunn Diode for battery charger
not sure, it's got to handle the current, they've got 3 legs, you could give it a try but better off with a power diode, cheers
very helpful. testing diode direction confused me but this vid helped
Cheers Jim, hope you've subscribed, cheers
Hi.
Are you in a position to tell me the ratings of the diods you have on such start-chargers? I am fixing one of my own... the diods are my unsolved equation. Thanks.
Hi, just go for a high current diode that fits your rectifier plates, no need for high voltage it's just the current, cheers
Where did you find new diodes? Were they a specific kind?
Hi, I just looked in my box of mixed diodes and chose one that looked right, cheers
man was that helpful hope the rest of the diodes in the box are bad
How can repair a rectifier for aq-tron charger
I'm not sure, either replace the solid state rectifier or find the blown diode and change that, subscribed? Cheers
14:50 curious about your reading on DC+ with the clamp meter. I thought those were used on A/c lines? I know there are some available for DC but not commonly available?
Hi, this one has both AC and DCcurrent functions, once you have one you would be lost without it for quick analytics. I hope you enjoy the rest of my video catalogue, Cheers
The diodes in that charger don't look big enough to do much more than a nice charge current - if someone has taken the word 'start' too literally, I am surprised _any_ of the 4 diodes has survived ! The transformer won't do starting current even slightly either ....
I know I mentioned this in your last charger repair vid Andy, but I drew the circuit out as you were pointing to bits in this one, and as far as I'm concerned the 12v output is _full wave_ rectified not half - wave rectified, just like the 24v. Though with one failed diode here, both outputs would indeed be only half wave rectified, hence the poor output :o)
Have a look at this google image : www.talkingelectronics.com/projects/70InterestingCircuits/images/6v_12vPowerSupply.gif
The bottom circuit is what you almost certainly have in your two chargers. Everywhere it says '6v', read that as '12v' , and where it says '12v' read that as '24v' for your chargers. Sorry, short of drawing it out for you myself, I couldn't find a better diagram of what you have on Google ! NB... _both_ outputs are full wave rectified ! Let me know if you need more explanation......
Cheers, Dave
Dave, yes I fully agree with you on the quality of the components, but it's a Clarke and so low end equipment. I suspect Sealy sell the same as it's own . Thanks for the link. I need to discuss this further. From my point of view there is no diode on the centre tap, but having considered your thoughts maybe the negative half of the wave is canelled out by the negative from the rectifier through the battery and so there is no current flow. This just leaves the positive with a path for the current to flow. Cheers, Andy
Clarke stuff is cheap and cheerful I guess ! I will have to give this some more thought Andy - as this dual voltage circuit is a combination of 2 types of rectification - one using 4 diodes in a bridge and the other using 2 diodes and a CT transformer secondary - we need to ignore the 24v output components when looking at the 12v output circuit, or it'll just be confusing... so ignore the two diodes that go to the 24v output, they do nothing at all when considering only the 12v output....ok ?
In one sentence - the 12v circuit can be thought of as 2 half wave rectification circuits combined together - each of these consists of one half of transformer secondary, one diode, and the load battery, and because of the way that each half of a CT secondary winding swings +ve and -ve alternately (think of the CT as a pivot point here) each half cycle, and, importantly, _out of phase with each other_ , each of the two half wave rect. loops is active for a different half cycle, so if you then connect these to half wave outputs together, the two waveforms interleave with each other and you get a full wave rectified output - bingo ! I'll email some more tomorrow when I'm more awake.... Dave
noakeswalker v
Hi
Hi
Thanks for the tip.