# rec ridge

Discussion in 'General Electronics Chat' started by bladerunner, Apr 8, 2014.

Apr 15, 2012
83
4
Am trying to figure out a circuit designed for a fencer. This fencer is old style and does not use circuit boards.

I have tested VDC and VAC on a line that is 120 VAC. Nothing else on it. The values I get is as follows: VDC = 0 and VAC = 120

I test the circuits by using the VDC mode since it had several rectifiers in the circuit. The problem is that I get a value on both VDC and VAC at the same point.

How can this be?

Have a great day :>)

2. ### MrChips Moderator

Oct 2, 2009
12,635
3,454
It depends on the testmeter. Some meters use rectifier diodes to convert VAC to VDC when measuring VAC. Hence you get readings when the meter is set to measure VAC and VDC.

3. ### #12 Expert

Nov 30, 2010
16,703
7,336
What kind of fencer? One that pokes other fencers with a type of sword or one that installs fences, or another kind?

Apr 15, 2012
83
4

Electric fence charger

#12 likes this.

Apr 15, 2012
83
4
This fencer has TWO source power 120VAC :

the first line to 'rectifier' to '10W 100 ohm block resistor' to 'rectifier' . At this point without anything else, the VDC =60. VAC =0. Now add another power source here 120VAC to another 'rectifier'(going the same way) to 10W 100 ohm Block resistor' to ' rectifier'. At this point the VDC is about 348. The VAC =0

Does this make sense?

Have a nice day :>)

6. ### #12 Expert

Nov 30, 2010
16,703
7,336
You either have both phases of the American 120 volt power line or a capacitor making a voltage doubler. (This is where schematics get important.)

Apr 15, 2012
83
4
am working on one but yes you are right. the source is attached to a transformer (yet identified). The output of the transformer is 120 VAC

The common source is also passed to two 5 uf cap in parallel producing 120 VAC.
As for the transformers, this fellow used about any that would give 120V output.

will get you a schematic in a few.

Have a nice day:>)

Apr 15, 2012
83
4
Here is a partial schematic.. Hope this helps. I did remove the second 120 V (coming from the caps) from the line. The vdc voltage at this point was 60.

Have a nice day :>)

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9. ### #12 Expert

Nov 30, 2010
16,703
7,336
Let me clean that up for you...

• ###### Fencer.png
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Apr 15, 2012
83
4

looks a whole lot nicer, guess you have done this a time or two( lol). My problem is while I am an electrician, I deal with home service, commercial and not electronics.

Do you agree with the 348 vdc at the end of the last rectifier.?

There is a Orange (Diode Looking) object that has a black strip at its center. This is not a diode but has something to do with blocking ac current. do you have any idea what it is called.

Have a nice day :>)