Perpetual Motion Holder As Induction coil/Transformer Help

[StwartMad]

I need help on why my SPDT automotive relay isn't buzzing when it is hook up to the Perpetual Motion Holder? Here is a drawing from someone on how he set up his relay to buzz for his ignition coil which is how I wired my relay except the only difference is I used a 0.047 uf non-polarized capacitor which I drew over the original image and used the PMH instead

[morpher44]

Relay as Chopper Circuit

I need help on why my SPDT automotive relay isn't buzzing when it is hook up to the Perpetual Motion Holder? Here is a drawing from someone on how he set up his relay to buzz for his ignition coil which is how I wired my relay except the only difference is I used a 0.047 uf non-polarized capacitor which I drew over the original image and used the PMH instead

In the past two weeks I've been experimenting with relays as chopper circuits.
Great fun.

Wire the relay as a buzzer -- meaning that when the metal clapper is
attracted to the solenoid, the circuit is broken, providing no power
to the solenoid.

Now connect the two leads from the COIL in the following way ...
One lead goes to a LARGER capacitance ... say 10MFD upwards
to 80MFD (AC, non-polarized capacitor). The other side of
the capacitor is wired to one lead of your coil under test.
The other lead of the coil under test back to the relay's other coil lead.

What occurs in this configuration is the following.
When the relay is in the disengaged state, power from the
battery has two branches it can take. It can go thru your
CAP-COIL or it can go to the relay's solenoid. A majority
of the power will go into charging up the CAP and the solenoid
will struggle to charge up magnetically. As the CAP becomes
charged, the relay starts to see more power. It eventually
can pull the clapper towards it, and then SNAP, a huge
pulse is released into your CAP-COIL.
All this is done w/o any silicon & is old-school ("Vibrator Power-Supply")
technology.

The timing constant of the CAP is simply resistance times capacitances ...
R * C
And you need about 5 * R * C for the capacitor to reach a
mostly charged state. Plugging in some numbers here ... suppose
your coil and wires, etc. have a resistance that adds up to 10ohms.
Suppose your capacitances is 40MFD.
10 Ohms * .000040 Farads * 5 = 2 milliseconds.
Frequency would therefore be 500 Hertz ... a little FAST for the relay.
So you can try for less Ohms ... or use a bigger cap to slow down
to say 40 to 100Hertz.

So I think the problem you are having boils down to simply using
a Capacitor that is too modest. You need bigger capacitance for a longer
time constant -- so that the relay can handle it mechanically.

[morpher44]

another useful trick

Another "old school" trick, inspired by the Hendershot stuff,
is you can take a MAGNET of appropriate size and bring it near
the relay. There are certain polarities and certain sweet spots you will
find that will make the relay BUZZ faster or slower.

Hence you can use this technique to "tune" to whatever chopping
frequency you want -- within the limits of the mechanical relay
and other factors.
It is so simple .. and again requires no silicon.

[Aaron]

pmh threads

There are other threads ALREADY on the PMH - please search for relevant threads before starting new ones.