Help designing CF lamp selector using momentary switches. Please!

[wad2k]

Hope someone can help:
I have three lamps(13w compact flourescent. Each driven by its own 12vdc electronic ballast) that I would like to switch on/off(*select only one to be on at a time) using 3 momentary switches(preferably spdt but I can use dpdt). Currenty I am using three SPDT "alternate action(non momentary)" switches with three non-latching relays. Doing it this way, all three lights can be on at the same time if all the switches are pushed in. I dont want it to work that way. I simply want to build a selector with three MOMENTARY switches....ie:

lamps A,B,C
And Switches A,B,C


When pushbutton"A" is pressed, lamp "A" goes on and lamps "B" and "C" should be off.

When pushbutton"B" is pressed, lamp "B" goes on and lamps "A" and "C" should be off.

When pushbutton"C" is pressed, lamp "C" goes on and lamps "A" and "B" should be off.

NOTE: The above "switching sequence" is not in any order...For example I may want to turn on Lamp "B" first..



Simple concept??? It is just a simple lamp selector using momentary switches


I thought about using 2 latching relays but I can't figure out how to make it work??

It would seem that using relays would be the best and most reliable way to do this but I am totally open to ANY designs!

I am also hoping to keep the cost under $150 and of course I really want it to last!
Any sugestions???

Thanks in advance!

PS Im glad I found this website...Alot of great info!

 

[VEBill]

The topic of using momentary switches to perform a latching function comes up constantly.

See thread:

http://www.eng-tips.com/viewthread.cfm?qid=100872

 

[wad2k]

Thanks for the reply! ...After looking at thread, it looks like an impulse , latching and/or ratchet relay(s) may be what I need.....now to figure that part out!
thanks!

 

[leonar40]

Instead of having three switches, you could just use one switch that has three positions. Typically you would see a switch like this that has an up, middle, and down position. You could then wire the same power supply into the switch and switch it out to the three different lamps. There would be no way that more than one lamp could be on at a time.

 

[VEBill]

The typical three-position toggle switch is DPDT and is 'off' in the middle.

 

[leonar40]

Ya come to think of it I guess you are right. I'm sure that there must be some 3 position switches though. What about something like you would see in a lamp that has three levels of brightness? Click-dim, click-medium, click-bright, click-off, repeat. Something like that?

 

[nbucska]

One or for production?

For one piece:

I would use e.g. AROMAT's AGQ1213 solid state relay with
CMOS or transistor logic, using a series C power supply
( 4diode bridge,one diagonal is input with series R and C
to the 110 AC. Other one to filter cap parallel with 10 V
Zener to supply the CMOS. From your budget -150- you
could buy the parts for 10 ( without PC board and switches)

For schematics, send fax#

<nbucska@pcperipherals DOT com> subj: eng-tips
read FAQ240-1032

 

[nbucska]

Sorry, AQH213


<nbucska@pcperipherals DOT com> subj: eng-tips
read FAQ240-1032