I'm just starting to design an A/B speaker switch, that will use a small 8 pin PIC (12F675) and a couple of latching relays, operated by any style of momentary push button switch. It will also provide LED indication of which speaker is selected. I will design a couple of PCBs to suit. Just testing to see if there would be any interest in this project - if so I will get a few more PCBs made at the time.
I'm still looking at options for the relays, but would be min 8A switching rating. Going for latching does seem to limit the options available (at least for high quality sealed), and I prefer to use latching in this operation. I was thinking about paralleling 2, but I've gone off this due to concerns if 1 relay fails and doesn't switch over. Although I guess you would notice this (both speakers playing), so maybe it isn't such a big deal and it might be better power handling/quality wise to parallel two. Your thoughts?
Happy to make the source code freely available - there's no rocket science in it - so you can change it as you see fit (eg I'm making it light up 1 or 2 LEDs depending upon which speaker is selected)
Happy to make the source code freely available - there's no rocket science in it - so you can change it as you see fit (eg I'm making it light up 1 or 2 LEDs depending upon which speaker is selected)
Why latching relays ? You really narrow your choices....
If you want to make something easy to build, go for standard relays (consumption is only 30-40 mA at 24 Volts).
If you go for e.g. FINDER Series 4061 (16A) relays, the special Amplimo (20/100A) speaker relay fit´s in.
www.amplimo.nl
If you want to make something easy to build, go for standard relays (consumption is only 30-40 mA at 24 Volts).
If you go for e.g. FINDER Series 4061 (16A) relays, the special Amplimo (20/100A) speaker relay fit´s in.
www.amplimo.nl
An externally hosted image should be here but it was not working when we last tested it.
Hi,
A stereo speaker selector I "designed" for my brother.
Switching the ground for speakers is not necesssary.
/sreten.
Why use a PIC at all ? Or latching relays?
You could probably design this easy enough using a 7474 or similar. Just have the push buttons change the set/reset pins. If you wanted a toggle you could connect D to *Q and have the push button drive CK (youd need to debounce it though and possibly one-shot it).
I dont see the point of using latching relays.. you can simply have the driving transistor for the relay coil held on. I guess using latching ones might save you power if youre planning to make it battery operated.
You could probably design this easy enough using a 7474 or similar. Just have the push buttons change the set/reset pins. If you wanted a toggle you could connect D to *Q and have the push button drive CK (youd need to debounce it though and possibly one-shot it).
I dont see the point of using latching relays.. you can simply have the driving transistor for the relay coil held on. I guess using latching ones might save you power if youre planning to make it battery operated.
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