How do i reduce the arc on the contacts ? I built a 2 cylinder engine and works perfectly until the contacts build up to much arc.

 

... As the points open up, the current flow, coming from the coil primary circuit, is abruptly terminated or stopped. The rapid change in primary side current flow ... through the ignition coil ... is somewhat like bringing a fast moving vehicle to an emergency stop. A lot of dynamic energy due to the established current flow, has to go someplace ... some of the energy is able to dissipate by creating a spark on the secondary side of the ignition coil. However, there is also a fraction of that dynamic energy which creates arcing at the points as they open up. The arc consists of high frequencies, rather than the original smooth current flow. These high frequency current components will pass through an automotive capacitance, usually referred to as a condenser, if the capacitor is connected between one side of the points mechanism and a good chassis ground. The only thing to be careful about is connecting one end of the capacitor between the ignition coil side of the points and the other end to chassis ground. The ground side typically requires a clamp of some sort ... a small hose clamp and a length of wire, going to a ground bolt should work. Be sure to use an automotive grade capacitor/condenser, since they can withstand the 500 volts typically encountered as the points open. Make sure no oil or grease is on any of the parts or you won't have good electrical conductivity ... a can of electrical contact cleaner spray might be a good investment.

 

If I understand your very vague question...

You have a motor that has electric solenoids attracting slugs of steel as "pistons"
There are contacts that get closed and opened by the crankshaft, these contacts are arcing.

Is that correct?

 

If I understand your very vague question...

You have a motor that has electric solenoids attracting slugs of steel as "pistons"
There are contacts that get closed and opened by the crankshaft, these contacts are arcing.

Is that correct?

You are 100% correct !

 

If i want to send a short video clip or photo to what adress must i send it to ?

 

... a slight misunderstanding of the situation, but the previous discourse may still be helpful.

 

Post a photo of your device and a schematic of how it's all connected here.

 

Use the 'Upload a file' button to post a picture here.
Connecting a capacitor across the contacts will reduce the arcing.

 

Post a photo of your device and a schematic of how it's all connected here.

 

Use the 'Upload a file' button to post a picture here.
Connecting a capacitor across the contacts will reduce the arcing.

Will try that. It runs off a18V supply. What size cap ?

 

 

 

You would be better using microswitches with levers,

 

... purchase automotive condenser at auto parts store ... usually about 0.22 uF.

 

Post a photo of your device and a schematic of how it's all connected here.

... purchase automotive condenser at auto parts store ... usually about 0.22 uF.

Will try that. It runs for about 2-3 min then it slows down and stops.

 

Connecting a capacitor across the contacts will reduce the arcing.

Or a diode across the solenoid - connected so it is reverse biased when the solenoid is energised.

 

agreed, just diodes across solenoids

 

Or a diode across the solenoid - connected so it is reverse biased when the solenoid is Will try that too. Thanks . Will ceep in touch.
Andrew.

 

... a reverse biased diode placed across the coil should work, but the 1N400x datasheet shows that the Maximum Recurrent Peak Reverse Voltage of that diode changes with the diode load current designation. You would have to get at least the 4 amp 1N4004 diode to get 400 volts reverse voltage protection, or better the 5 Amp 1N4005 to get 600 reverse volts as specified by the datasheet.

 

The diode only needs to be a bit higher than the supply voltage and only needs to handle a bit more than the max current the solenoids draw.

Bob