Relay Replacement - Which part?

Thread Starter

RolandSCH

Joined Nov 20, 2017
3
Hi, I'm trying to repair and recap a pair of speakers and I need to replace the relays due to some errors (probably bad connections in the relay).
The problem is that I can't seem to find a suitable replacement part in Europe.

Schematic and pictures of the relay are attached.

I'd be great if any of you could point me in the right direction!
Thanks
 

Attachments

Marley

Joined Apr 4, 2016
502
This is a 6V 400 ohm coil relay with a single N.O. contact (SPNO). Should be possible to get something similar. The important thing is to have the correct PCB pin arrangement. Can you carefully measure and provide a close-up photo of the PCB and the relay pins?

Are you sure the relays are faulty? Have you tested them?
 

Reloadron

Joined Jan 15, 2015
7,501
That is a pretty common Guardian relay having a 6 volt 400 ohm coil. I would think any of several parts distributors in Europe would stock it. I see them on Ebay here in the US as well as as distributors like Mouser. Hopefully someopne from your side of the pond will suggest a distributor in Europe.

Ron
 

Thread Starter

RolandSCH

Joined Nov 20, 2017
3
Thanks! @Relaodron could you provide me a link to the mouser or eBay site where you found them? Nothing really comes up in my search. Mouser.com returns only 1 result for "Guardian"
 

Thread Starter

RolandSCH

Joined Nov 20, 2017
3
This is a 6V 400 ohm coil relay with a single N.O. contact (SPNO). Should be possible to get something similar. The important thing is to have the correct PCB pin arrangement. Can you carefully measure and provide a close-up photo of the PCB and the relay pins?

Are you sure the relays are faulty? Have you tested them?

I'm pretty sure it's not working properly. I can hear a scratching/distorted sound from time to time in one tweeter, which disappears when I crank the speakers for a second
 

Attachments

Reloadron

Joined Jan 15, 2015
7,501
I Googled "Guardian 1345 Series Relay" and got results like this one. The 1345 is a series and the additional numbers define the contacts and coil voltages, you want a 400 Ohm 6 Volt coil single pole double throw from the looks of it. Wish I could find the data sheet with the pin spacing as printed circuit board mounted relays are common.

From Mouser I think this will work for you. Here is the data sheet with the dimensions. There are likely other manufacturers. Coil Voltage is 6V but the resistance is lower so the coil will draw more current.

Ron
 

Lyonspride

Joined Jan 6, 2014
137
Guardian 1345 series, but as mentioned above you need to measure the pins and find an alternative....... Or you could have any relay you want out on flying leads from the PCB, something i've done on occasion when I need a quick fix.
 

zavan

Joined Jul 24, 2018
2
Hi, did anyone find a solution? Is this really a NO? Does it matter on the circuit if the resistance will be lower? With other relays might we have some "on/off timing" problems?
 

Reloadron

Joined Jan 15, 2015
7,501
Hi, did anyone find a solution? Is this really a NO? Does it matter on the circuit if the resistance will be lower? With other relays might we have some "on/off timing" problems?
Just suggestions but nothing concrete where I am willing to say something will absolutely, without a doubt be a direct plug in replacement.

Ron
 

zavan

Joined Jul 24, 2018
2
This is the circuit with it's parts. If someone would put a 6v 10A relay but different ohm than 400 (probably much lower) is there a part that needs to change to compensate this change?
 

Attachments

Reloadron

Joined Jan 15, 2015
7,501
The relays are transistor driven. With a 6 volt coil and a 400 Ohm coil resistance the coil current will be about 15 mA switched by the transistor. This is the transistor data sheet. The lower the coil resistance the more current the coil will draw and that current needs to be supplied by the driving transistor. You could likely half the coil resistance and get away with it.

Ron
 
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