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Forum Index : Other Stuff : Gallagher M120 3W 240V fence charger
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| domwild Guru  Joined: 16/12/2005 Location: AustraliaPosts: 873 |
Hi, My fence charger is no longer ticking. Have checked it, could not find a fuse, no bulging cap(s), no smoke has escaped, no clue. Help! As some of the you live in the bush and may even have built your own, I thought it best to ask here. By the way, I have not managed to kill myself with 240VAC, so do not print my obituary yet. Is there a simple way to test what has failed or is it known what most likely has failed? Thanks. Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up. Winston Churchill |
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TassyJim Guru Joined: 07/08/2011 Location: AustraliaPosts: 6098 |
They don't have many parts usually. Do a google for "electric fence circuit diagram" and you will get a few examples. The last one I saw apart was mine when it got destroyed by lightning. I now use a solar powered on to keep the nasties away from the house. The capacitors can hold a nasty charge for a long time! Jim VK7JH MMedit  MMBasic Help |
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| Boppa Guru Joined: 08/11/2016 Location: AustraliaPosts: 814 |
I used to build/repair electric fences many yeas ago, and 99% of them were damaged driver transistors/mosfets (usually after a spate of thunderstorms) or failed storage caps (usually after a heatwave), the rest were usually corrosion issues where the case had been damaged and filled with water- the damage on those was pretty obvious why they stopped working  Usually the power supply is either a separate board if inbuilt mains, or at least a separated part of the pcb, usually it can be isolated from the rest of the main drive circuits and checked for any output, then move to the oscillator circuitry (best checked with the driver transistor or mosfet disconnected if possible) for its output, check the transformer for continuity and the driver transistor/ mosfet for s/c or o/c (s/c was more common in my experience) |
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Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1023 |
Doing some repair myself on a similar fencer to this one here lists some common problems. Also going to build one of those that use the 2 555 timers, see how it works. Cheers Aaron Off The Grid |
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| domwild Guru Joined: 16/12/2005 Location: AustraliaPosts: 873 |
Thanks for the generous help from the forum. As a former IT lecturer I am more of a software man with limited electronics, so I am wondering what Gallagher comes up with re repairs in Perth as they tell me to ring Melbourne?? Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up. Winston Churchill |
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Chopperp Guru Joined: 03/01/2018 Location: AustraliaPosts: 1057 |
Speaking from experience, Jim? ChopperP |
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yahoo2 Guru Joined: 05/04/2011 Location: AustraliaPosts: 1166 |
I tracked my fault in a fence energizer to the pulsed capacitors. the AC cap in front is fine and the big one on the left is OK it was one of the two with the arrow. This energizer has some extra guff, some charge shaping and every six zap is a big one.  https://www.wiltronics.com.au/product-category/electric-fence-capacitors-high-grade-pulse-type/ I'm confused, no wait... maybe I'm not... |
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| domwild Guru Joined: 16/12/2005 Location: AustraliaPosts: 873 |
Thanks Yahoo2. I will have another look, but from memory I just saw one big one, like the one in the Wiltronics catalogue. Can I after discharging any left-over nasties just check it like any other cap? Do I need to snip the two wires first or can I leave the wires connected to the board? Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up. Winston Churchill |
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| yahoo2 Guru Joined: 05/04/2011 Location: AustraliaPosts: 1166 |
Mine had bleed down resistors and they were working. this energizer was still triggering the SCR's and ticking.But that could be because it has 3 massive caps. I think it fires the scr based on the voltage in the cap I honestly dont remember how I tested them. someone told me how to check them in circuit sadly I have forgotten the procedure. you might be able to unsolder one wire and clip a temporary cap in circuit, jump some wire across the high volt output screw terminals and see if it ticks. I spent a lot of time checking the diodes, coil and transformer and got nowhere. I was able to trace the path from the ac input through a Mov (varistor) into diodes then voltage reg into the transformer and out to the caps https://www.thebackshed.com/forum/forum_posts.asp?TID=7849 original post with more photos Gallagher sell the modules, boards and caps, from memory there was an official repairer in bendigo or ballarat I got his number from the Lyco sales rep through Wesfarmers stock agents. edit: I think yours would have a PWM bit in the circuit rather than the regulators to save power. I'm confused, no wait... maybe I'm not... |
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| ffindog Newbie  Joined: 22/01/2019 Location: AustraliaPosts: 3 |
A common fault on modern Gallagher units is the transformer fails. Unfortunately There’s no off the shelf drop in replacement available. There’s a guy that retro fits a transformer from a different unit for them. His name and company name are eluding me at the moment. The photos are one of the units we got back from him. The pin out on the replacement transformer are different hence the cut tracks and jumper wires. if it turns out to be the transformer you might be able to use the photos to replace it.   |
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| domwild Guru Joined: 16/12/2005 Location: AustraliaPosts: 873 |
Thanks for help. I will concentrate on the large capacitor first as I now have a catalogue of similar units, thanks. If I am unsuccessful, then I may have to buy a new one, probably "Made in China". Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up. Winston Churchill |
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| domwild Guru Joined: 16/12/2005 Location: AustraliaPosts: 873 |
Gallagher says the unit has to be sent East. The large cap seems to be OK, without snipping the wires and the meter set to max. Ohms, the figure starts low, then rises and cuts back to zero, so the cap is OK. So it could be the transformer. Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up. Winston Churchill |
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| Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1023 |
Can you post a photo of the board? would be good to see the layout. Most of these 240vac fencers follow a similar working principal, but not all. The one I have has a large cap, also tests ok, had it powered up (BEWARE HIGH VOLTAGE) checked with DMM, 600v at the big cap, at the limits of the DMM.  the small cap was supposed to trigger the SCR on the one I have, But the SCR on mine is shot, some small ants walked across the tracks under the SCR. I guess the gate copped too much voltage. Cheers Aaron Off The Grid |
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| domwild Guru Joined: 16/12/2005 Location: AustraliaPosts: 873 |
This is the official Gallagher reply: "All Gallagher repairs come back to our offices in Epping Vic for assessment/repair. The best bet is to take it to your local Gallagher re-seller who will arrange for it to come back here for you. Once it arrives we will assess it and provide you with a quote for repair, there will also be a trade up option for an equivalent new unit at a discounted price. You can then decide if you would like to get the unit repaired, trade up or ask us to dispose of the unit or send it back un-repaired." Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up. Winston Churchill |
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| Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1023 |
After reading that, A solar or battery electric fence unit is looking better.  I have to fix a Gallagher solar s17, The little solar panel has failed after years of service, I was tempted to ask Gallagher about it, I guess I would get about the same answer. Cheers Aaron Off The Grid |
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| domwild Guru Joined: 16/12/2005 Location: AustraliaPosts: 873 |
My sincerest apologies for wasting every bodies time here. After disconnecting the fence wires, testing a cap and even pulling the board off I switched the unit on - surprise, it ticked! So I walked along the fence to find the fault, voila, an earth wire had wound itself around the live wire. Should have remembered the following: The dimmer the right hand LED is, the less resistance is in the fence system, like with wet grass reaching the live wire. And it follows from that, if that LED is completely dim, I have a wire problem most likely. At least, I have learned how to test the unit and I am still waiting for the answer from Gallagher if parts like the drop-in transformer can be bought. Thanks for help. Try to avoid old age! My GP tells me they have not yet found a cure for stupidity. Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up. Winston Churchill |
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