DIY Tesla Switch Guide

[gmeast]

Hi Greg,

I think you are right, there is a misprint in that schematic. The correct way would be for the lower contact of the light bulb would connect to the common negative of bats 3 and 4 instead of their common positive shown?
Have not figured out.

rgds, Gyula

Yes ... and more than that.  BOTH the + bus and - bus in this parallel connection of batts 3 & 4 must be connected to something or it's still OUT of the circuit.

Anyone else?  Thanks,

Greg

[geotron]

crowclaw meant the lower relay contact
goes directly down to the negative battery polarity, ok?

- Ok... as shown? My interpretation of GND is (-)

The 1 kOhm
and its connection is ok to the upper relay contact.

||||

The 12V
goes directly to the timer input of the Tesla switch
via the 1 kOhm
and whenever the relay is fired, the timer input
is connected to

the negative polarity instead of the +12V.

So besides my previous lower relay connection I have correctly
illustrated the correct way to time this device?

In your drawing the wire from the lower relay contact
now goes to the 1000uF capacitor,  this is wrong

that wire should go to the GND instead
of the cap.

The GND below the cap, or as I have connected below,
to the one on the timer circuit?

[gyulasun]

@geotron

Yes, that is how crowclaw meant connecting the timer output to the input of the T switch.  The two GNDs are also connected of course.

[crowclaw]

Hi crowclaw,

Very good, and  am curious what capacitors you use now: your 18000uFs?

I also wonder if supercaps are a must in their circuit (probably this depends on the heavyness of the load) and I agree the switching frequency is critical (charge/discharge time of the capacitors and harmony with the load). 

When you turn to solid state switches, have to face with the body diode in MOSFETs, and the 1V or higher ON state voltage drops of the SCRs. Prepared for them?

rgds,  Gyula

Hi Gyula,

Yes your right of course about using solid state device types! sometimes my ideas surpass logical thought processes. The caps I have had kicking around for years and I don't remember how I came by them... they are 18000uf @ 30v with screw caps and rather large. I have three of them being used for this experiment. Yes the timing is critical as two in parallel across 12volts to charge up takes quite an initial drain... they are then discharged in series across the battery as per diagram.

If any one else wants to jump in with thoughts and suggestions please feel free. Regards

[geotron]

It's a bit crooked, but this is my working model of the
Louis Pollaehn timer.

I have labeled the components to the best of my
visual interpretation - the resistor between pin 5
of cd4011 and the 1M speed control was guessy, as
well as the one by 2n2222.

The high speed diode ? - across from the relay
is curious... Would a 1N914 work?