ATOM Diy module

[KeepItSimpleStupid]

The KIT generally consists of an (electrical insulator/thermal conductor), a Belleville domed washer, a shoulder washer a machine screw and a nut.
A "shoulder washer" is shown here: https://www.biscoind.com/RAF/5745-N-250-125-144

It's designed for a heat sink such as: https://www.mouser.com/ds/2/303/sink_ex-1076311.pdf

You can blind tap a hole in thick material if required. "blind tap" - A tapped non-thru hole. They are harder to do.

I don't know what your options are.

 

[KeepItSimpleStupid]

Would like to use same hole in transistor to mount to aluminum heatsink and to metal of saw

Use a longer screw. The "heat sink" aluminum would have a clearance hole for the size as the screw. The screw could be longer if need be.

 

[tysman]

K thanks

 

[tysman]

i used an ST901T in one of my modules works great lots of rpm in my chainsaw so as an alternative it will work in place of D1071

 

[debe]

Thanks for that feed back on a successful replacement transistor.

 

[tysman]

yup specs on it to says made for ignition systems like chainsaws, lawnmowers, etc. says its rugged to

 

[tysman]

Made a module for a buddies saw and for some reason had to switch wires around do I leave the spike protector the same or do I flip it to. Also noticed that it reads a resistance of 3.10 both ways normally diode should only read 1 way.

 

[tysman]

also spark on module is weaker then points which seems weird

 

[debe]

You have a problem some where. The diode out of circuit should read about 20 ohms one way & infinity the other. As an assembled unit mine read 20 ohms one way & 90 ohms the other way.

 

[tysman]

when i hooked module up to saw there was a faint spark when i hooked gnd up did i damage module? and thats why spark is weak and weird readings on diode? the saw runs with wires switched seems like no top end but i do have wrong plug in engine which makes difference

 

[tysman]

also im using a DPDT switch so can switch from points to module with switch 1 way module is in use and points disconnected and with switch other way then points in use and module disconnected the coil is middle pin on switch. if i damaged something on module to make spark weaker what should i change or check on module?

 

[tysman]

Looks like everything is fine soldered new transistors in same outcome um so for some reason wants to run with wires switched do I leave the diode alone or switch it to? Also the points side is still stronger more rpm then module. I'm thinking timing related this flywheel has tighter gap on magnets

 

[debe]

Have you wired the spike protector to the module around the wrong way? Perhaps post pictures of your module.

 

[tysman]

Spike protector is same way as your diagram I just switched wires. Timing seems off no top end

 

[tysman]

Any sorta timing adjust with resistors to make spark hotter or increase in rpm?

 

[debe]

Not that I know off. But some pictures of your module & the chainsaw flywheel & Coil might be of some help.

 

[tysman]

OK I will take pic of flywheel and coil.

 

[tysman]

Here's flywheel

**broken link removed**

 

[tysman]

those Nova Modules i dont think have timing resistors what would happen if it was just the switching transistor and the bc337. i have a pic of a blue coil taken apart and those 2 components where only thing inside no caps or resistors

 

[tysman]

cause gap in flywheel is slightly tighter i think i need to retard timing by a little is this correct?