Nikon D40 compatibilty with Sunpak flash units

Hi guys, Newbie here. I have two Sunpak flash units that I use with my Nikon FA. One is the Auto 433 D and the other is the Auto DX 8R ring lite. I want to use them with the Nikon D40, my worry is that the electronc circuitry may not be compatible and I might burn out the circut board in the camera.
Any input will be greatly appreciated

I'm guessing the D40 doesn't have a PC plug, so I'm assuming you're using a hot shoe adaptor? You're probably find using them on manual or auto but I'd avoid trying to use them with any dedication or TTL settings they may have.

Hi Steve: Thanks for the come back, your right no pc plug, it has a built in flash with accessory shoe. Ill go the manual route with the ring lite and see what results I get.

Thanks again
Pete

You MUST check the trigger voltage on SOME old flash guns like very old Japanese Vivitar 283's - there is a site which can find on google which has trigger voltages of various guns .

The best bet is a Wein Safe Sync Adaptor . I lent somebody one to use on his Dad's Canon at my mate's wedding to use with my old Metz CT4 gun .

You can also check with a cheap voltage meter . Apparently some Canons can have their electronics fried with old flash guns .
Nikons are generally OK up to 250 volts .

AFAIK with old guns you have to use the old film technology and hope for the best on AUTO . I very much doubt if the gun is advanced enough to " talk to " the Nikon D40 .

You can check the preview screen and adjust accordingly , at least you're not wasting good film with the D40 .

Nikkormat: I googled this site like you suggested. http://www.botzilla.com/photo/strobeVolts.html

There is a wealth of information there. Following the instructions given I was able to determin the voltage on my unit (5volts)which would make it safe to use. Now its trial and error to see if I can get camera and flash to work as a team. Like you said, I wont be wasting film.

Thanks for the help.
Pete