Assuming the transformer is marked then you shouldn't be making a mistake, if it's wound & marked correctly that is. If it isn't then if you happened to connect a secondary winding to what is you ground in your circuit you get 9V from one diode & 18V from the other.
Having been involved in the manufacture of 3 phase industrial battery chargers you'd be surprised at the number of transformers that are wound & terminated incorrectly 😀
Ok the resistance from gnd to anode of the diodes is 2 ohm for both the diodes. What does this mean ? Does it mean DOOMSDAY for me ?
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OMG such things can happen ? The transformer is marked with 9-0-9 on each pin respectively. Now i beginning to doubt if they did something wrong.
It sounds like it's ok to me with those resistance readings. If it was wrong i'd expect the reading at one diode to read 2 ohm & the other to read 4 ohm, so i think we can forget that 😉 It appears to be correct, which leads to a lot of head scratching 😕
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Head scratching ? I am banging my head on a wall already !!! Haha. Is there any more info i could provide ?
OK Buzzy, here's what to do... and I am going off your circuit... sorry if it's repetitive 🙂
Those resistance readings sound OK too.
Without having it front of me, we need as much info as possible.
Copy and paste this, and fill in the answers lol sorry .... 😉
With the circuit all wired up and working... you said it works,
First connect the negative lead of your meter to the negative end of C1 and then leave it there and DON'T move it. Expected readings in brackets.
1. Meter on DC. What is the DC volts on positive end C1........ (approx 12vdc)
2. Meter on DC. What is the DC volts on cathode of D1.......... (identical to above)
3. Meter on DC. What is the DC volts on cathode of D2.......... (identical to number 1)
4. Meter on AC. What is the AC volts on anode of D1............. (approx 9vac)
5. Meter on AC. What is the AC volts on anode of D2............. (approx 9vac)
6. Meter on AC. What is the AC volts on transformer center.... (zero)
7 Meter on DC. What is the DC volts on transformer center.... (zero)
If your readings don't agree with those 🙂 well see what you get...
Those resistance readings sound OK too.
Without having it front of me, we need as much info as possible.
Copy and paste this, and fill in the answers lol sorry .... 😉
With the circuit all wired up and working... you said it works,
First connect the negative lead of your meter to the negative end of C1 and then leave it there and DON'T move it. Expected readings in brackets.
1. Meter on DC. What is the DC volts on positive end C1........ (approx 12vdc)
2. Meter on DC. What is the DC volts on cathode of D1.......... (identical to above)
3. Meter on DC. What is the DC volts on cathode of D2.......... (identical to number 1)
4. Meter on AC. What is the AC volts on anode of D1............. (approx 9vac)
5. Meter on AC. What is the AC volts on anode of D2............. (approx 9vac)
6. Meter on AC. What is the AC volts on transformer center.... (zero)
7 Meter on DC. What is the DC volts on transformer center.... (zero)
If your readings don't agree with those 🙂 well see what you get...
Oh no ! I saw some liquid coming out from the C1. I need to get a new one. Any idea what would cause the liquid to come out ?
disconnect the transformer.
Check it thoroughly.
Wire up a bulb tester and use it to power everytime until your are sure EVERYTHING you have added or changed is correct.
Now place all the wires of your transformer into individual terminals of an insulated terminal block.
Wire up a mains plug top with a small fuse (3A ?) and connect it between the bulb tester and the mains input connections of the transformer. Switch on power at the wall to feed the bulb tester.
Is the bulb lit or glowing or off?
Did the bulb flash or glow momentarily?
What is the voltage across each of the secondary terminals. Label them A, B, C.
read the AC voltage across all three combinations.
Tell us what you have found.
Two things... it's in back to front... or the voltage rating is too low... or both... or it's not really leaking at all and you spilled your favourite tipple over it in the excitement 🙂
hi,maby one of the diodes is shorted or reverst in its postion?use the diode check function on youre dmm to check.a good diode will show somthing arround 0.6 volts.
Where is the other side of the "9-0-9V" connected ??
There must be three pins at the transformer for this connections.
If one half of this dual transformer winding is in the idling (i. e. without load current) the ac voltage must be higher than the other ac voltage half connected to your circuit.
But this is only true if is the 0V transformer terminal and the reference point for your measurements is connected to GND
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Please ignore this comment, because I haven't see all the other comments at that time, when I created the text !!! I have see only page 1 from post #1 to #10
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