Gabs Posted November 20, 2018 Author Share Posted November 20, 2018 16 minutes ago, MrHappy said: Revann Electronics ? Yes, I think so. Why? Quote Link to comment Share on other sites More sharing options...
al-yeti Posted November 20, 2018 Share Posted November 20, 2018 Just now, Gabs said: Yes, I think so. Why? He's just a alarm enthusiast got nothing better to do Quote Link to comment Share on other sites More sharing options...
sixwheeledbeast Posted November 20, 2018 Share Posted November 20, 2018 1 hour ago, Nova-Security said: My typo meant 4047 Could do it with a 555 if you could get the mark/space ratio equal, one LED to + rail the other to - Yes, a 4047. I find a 555 much more flexible in a smaller package. You are right tho it's the right chip for a 50% duty cycle multivibrator. 57 minutes ago, Gabs said: I was thinking of using a betray like this: https://uk.rs-online.com/web/p/coin-button-rechargeable-batteries/0525815/ bit safer than a Lithium one. I was thinking of a 7.2V NiCd/NiMH like most alarm bells do. While it is listed as Li-ion charger circuit it would be suitable for other cells. Actually, I would say it's more suited to Ni cells. Quote Link to comment Share on other sites More sharing options...
Gabs Posted November 20, 2018 Author Share Posted November 20, 2018 4 minutes ago, sixwheeledbeast said: Yes, a 4047. I find a 555 much more flexible in a smaller package. You are right tho it's the right chip for a 50% duty cycle multivibrator. I was thinking of a 7.2V NiCd/NiMH like most alarm bells do. While it is listed as Li-ion charger circuit it would be suitable for other cells. Actually, I would say it's more suited to Ni cells. I will take that into consideration, those cells are much safer than lithium ones, but I'm surprised at how little there is in the way of circuitry on the board of the SAB I have, is the battery constantly charged until needed? I have ordered the relay I will be using for my circuit Quote Link to comment Share on other sites More sharing options...
sixwheeledbeast Posted November 20, 2018 Share Posted November 20, 2018 8 minutes ago, Gabs said: I'm surprised at how little there is in the way of circuitry on the board of the SAB I have Possibly an SCB, from looking at the traces in the photos. Battery negative runs into the contact of the relay? Says Leyland on the buses but they don't all go there... Quote Link to comment Share on other sites More sharing options...
Gabs Posted November 20, 2018 Author Share Posted November 20, 2018 6 minutes ago, sixwheeledbeast said: Possibly an SCB, from looking at the traces in the photos. Battery negative runs into the contact of the relay? Says Leyland on the buses but they don't all go there... Yeah, that is correct, the negative of the battery goes into the relay. It would be very easy to make a bell module with no charging circuit, you'd only need a relay. Board looks hand-etched too. And it could be SCB, it is powering a bell, not an electronic siren, so I can't imagine that battery lasting long anyway. It amazingly still holds a charge. Quote Link to comment Share on other sites More sharing options...
Gabs Posted November 20, 2018 Author Share Posted November 20, 2018 Think I have cracked the part without the battery charging circuit, really quite simple Quote Link to comment Share on other sites More sharing options...
sixwheeledbeast Posted November 20, 2018 Share Posted November 20, 2018 Would normally be a single -ve applied for the trig. Quote Link to comment Share on other sites More sharing options...
MrHappy Posted November 20, 2018 Share Posted November 20, 2018 1 hour ago, Gabs said: Yes, I think so. Why? never seen anything or heard of this co. before, however 01297445 REVDUN ELECTRONICS LIMITED Dissolved 22/05/1993 01907384 REVDUN SECURITY PRODUCTS LTD. Dissolved 06/11/1990 Google throws up your topic on here about a panel & a linkdin page which say they where in Birmingham ? Quote Mr Veritas God Link to comment Share on other sites More sharing options...
al-yeti Posted November 21, 2018 Share Posted November 21, 2018 2 hours ago, MrHappy said: never seen anything or heard of this co. before, however 01297445 REVDUN ELECTRONICS LIMITED Dissolved 22/05/1993 01907384 REVDUN SECURITY PRODUCTS LTD. Dissolved 06/11/1990 Google throws up your topic on here about a panel & a linkdin page which say they where in Birmingham ? Stalker Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.