Trouble controlling two lights with relays

Hello,

I'm trying to make a device that controls two lights. There are two
switches and each controls one of the lights (i.e. SW1 controls LED1).

So, if SW1 is pressed, LED1 will turn on. A second press of SW1 will
deactivate LED1.

Also, I never want both lights to be on at the same time.

If SW2 is pressed while LED1 is on, LED1 will turn off and LED2 will
turn on. A second press of SW2 will deactivate LED2.

I plan to use momentary tact switches, so the latching can't come from
something like toggle switches.

And for more fun: if the power goes out, I don't want either lights to
be on when the power comes back on.

I've been trying to make it work with relays (without any luck). Has
anyone tried this before? Any help would be greatly appreciated.

Thanks in advance,
Chris Kirchen

 

I've been trying to make it work with relays (without any luck). Has

This should work, although it's almost certainly not the most efficient
solution. View in fixed font:

+ -
| SW 1 |
| T C1 |
| --- +|| RY A |
|-o o-------------||----------------------------------( )-------|
| || |
| |
| CRY A CRY C RY B |
|-----| |-----| |-------------------------------------( )-------|
| |
| CRY A CRY B CRY F RY C |
|-----| |---o-|/|----------|/|------------------------( )-------|
| | |
| CRY C | |
|-----| |---' |
| |
| SW 2 |
| T C2 |
| --- +|| RY D |
|-o o-------------||----------------------------------( )-------|
| || |
| |
| CRY D CRY F RY E |
|-----| |-----| |-------------------------------------( )-------|
| |
| CRY D CRY E CRY C RY F |
|-----| |---o-|/|----------|/|------------------------( )-------|
| | |
| CRY F | |
|-----| |---' |
| CRY C LED 1 |
|----------------| |----------------------->|-------------------|
| |
| |
| CRY D LED 2 |
|----------------| |----------------------->|-------------------|
| |

created by Andy´s ASCII-Circuit v1.22.310103 Beta www.tech-chat.de

A few tricks to this one -- it works only with DC, you'll have to play with the
value of C1/C2 to get as brief a pulse as will work, and you need a 4-pole
relay for RY C and RY F. Use two relays if you need to.

This isn't the most efficient system, but it will work. Digital logic next
time, okay?

Good luck.
Chris

 

This should work

Ooops. Forgot a few things. If you're using a cap as a one-shot former, you
need to wrap a resistor (say, 22K) around it to allow the cap to discharge.
Also, you need series resistors for the LEDs. Here's a quick mod on the above
ckt (read in fixed font)


+ -
| |
| |
| ___ |
| -|___|- |
| SW 1 | | |
| T | C1 | |
| --- | +|| | RY A |
|-o o-------------||----------------------------------( )-------|
| || |
| |
| CRY A CRY C RY B |
|-----| |-----| |-------------------------------------( )-------|
| |
| CRY A CRY B CRY F RY C |
|-----| |---o-|/|----------|/|------------------------( )-------|
| | |
| CRY C | |
|-----| |---' |
| |
| ___ |
| -|___|- |
| SW 2 | | |
| T | C2 | |
| --- | +|| | RY D |
|-o o-------------||----------------------------------( )-------|
| || |
| |
| CRY D CRY F RY E |
|-----| |-----| |-------------------------------------( )-------|
| |
| CRY D CRY E CRY C RY F |
|-----| |---o-|/|----------|/|------------------------( )-------|
| | |
| CRY F | |
|-----| |---' |
| CRY C ___ LED 1 |
|----------------| |-------|___|----------->|-------------------|
| |
| |
| CRY D ___ LED 2 |
|----------------| |-------|___|----------->|-------------------|
| |

created by Andy´s ASCII-Circuit v1.22.310103 Beta www.tech-chat.de

Good luck.
Chris