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  1. T

    replace a 9v power outage backup sorce

    here are the traces that I can find. blue and red traces originate at 24vac lugs. orange circle = fuse , green = 100uf 6v cap.(one side to red trace and the other to blue trace), lime = what I think is a diode, it has a clear casing with two copper colored rings inside with a very small...
  2. T

    replace a 9v power outage backup sorce

    here are the traces that I can find. blue and red traces originate at 24vac lugs. orange circle = fuse , green = 100uf 6v cap.(one side to red trace and the other to blue trace), lime = what I think is a diode, it has a clear casing with two copper colored rings inside with a very small...
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    replace a 9v power outage backup sorce

    here are the resized photos. they are the front and back of the piggyback power board. the other board has the power distributions for the individual valves and the control for the system. With the unit active, power on, there is almost no voltage at the 9v power connector, 120 mv. There is...
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    replace a 9v power outage backup sorce

    wow! I thought we had it, but looking inside I cannot even see anything that resembles a full wave rectifier! there are only 2 diode present on the power board. the 24vac comes in , through a fuse and straight to the black lead of the battery connector. the other side of the ac goes through 2...
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    replace a 9v power outage backup sorce

    OK. I think I've got it this time. Open up the electronics and find the full wave rectified ac to dc point to connect to, and hopefully it's also buffered to make a smoother signal. Then use that as the power source for your add on circuit. Connect it in parallel with the existing battery...
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    replace a 9v power outage backup sorce

    thanks for the heads up.
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    replace a 9v power outage backup sorce

    Thanks for your help. I like this simple circuit, it will fit easily in the box. but I do have one question, it appears that the circuit is doing a half wave rectification. but you have stated that this circuit works well on a 24 (dc), not (ac) supply. I don't know whats inside the box, but I do...
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    replace a 9v power outage backup sorce

    I have an older water controller for a sprinkler system. It's working voltage is 24vAC that is quite normal and common. The electronics portion has a 9v (DC) battery supply that keeps it's memory and program intact during a power failure. Most of our power failures are nothing more than a...
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    diac troubles in a heater circuit

    Thanks so much for the help and info. I ordered a db3 this morning. Sorry I wasn't more clear for the drawing, it is one I found on the internet that just happens to be exactly as my circuit except for the values of the components. that is why the components were stated out. thanks again.
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    diac troubles in a heater circuit

    I have a rather simple circuit that controls heating elements. After testing each component, I find them all good except the r20 (47 ohms resistor And the diac.( the diac show a few ohms in each direction when tested with an ohm meter). I have replaced the 47 ohm resistor but don't have an idea...
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