View Full Version : Mechanical Relays On The 595 Board???

11-12-2008, 07:43 PM
Can I use mechanical relays on the 595 board???
I would relay like to use them!
If so do I just connect the relays to the output of the 595, with a diode across it?
I know you all don't really recommend mechanical but I just want to know if it will work or not!
Thank You

11-13-2008, 12:23 PM
I don't know about specifically using mechanical relays on the grinch, but I built my own olsen 595 with 48 channels that uses all mechanical relays. I've been able to do this successfully for 2 years now, with no relay failures, yet (but I have spares). I've had no problem running sequences at 50ms, in below zero weather. There are a few things that you have to watch for though.... I'm using PC board relays that I got from china. They draw more mA than the 595 chip can handle, so I have to use NPN transistors to sink more current. Then you also need to add a diode in the right direction on the relay as well.

Considering shipping costs, price of relays, transistors, diodes, and the hassle of all getting it all right, you might as well get the stuff for ssrs. I've slowly started changing over to renards. I'll just be sad to no longer use the 100 relays that i'll eventually have laying around.

Though, when you cycle through a bank of 48 relays, it's candy for the eyes and EARS.

11-13-2008, 01:44 PM
As long as the relays meet the specs of the 595 outputs you should be fine.

11-13-2008, 03:14 PM
Actually, this is what I was doing for testers that I used at work five years ago. We use 24 VAC and I was looking to see if there was another way to control 120 VAC. That’s when I found ComputerChristmas.com and discover TRIAC’s. I was using ULN2803A driver chips right off the 595 chips. They can control up to 1/2 an amp DC directly and work at up to 60 volts.

11-22-2008, 02:28 PM
i have mine running on mechs for the 24v lights
is there an ssr that can be made to power these lights

also im having loads ov channels flikkering on and off
when is runnin on vixen ?