single switch, multiple outputs

Ok, Kind of have a weird idea, but not sure if there is an easier way to do it, or if I will have to use a bunch of relays. I have a customer that added after market power windows to his car. He has 2 momentary rocker switches (ON)-Off-(ON), but wants to be able to use those same switches to control other things in his car. I tried to figure out how to go about it using a 3 position ON-Off-ON rocker. The problem I keep running into is that when the latched rocker is in the off position, for the power windows to work as normal. The other part that I would like to find an easier method for is cutting down on the number of relays for the whole thing. If it is possible. So basically what he wants to do is have the latched 3 way rocker be in the off position, power windows are controlled by the momentary rockers, but when he switches the latched 3 way rocker to ON in one direction, he can control his 2 linear actuators forward and backwards through the window switches. Then with the latched 3 way rocker in the other ON position, to control his air bags. So a total of 3 rockers to control 6 different things. 2 momentary rockers and 1 latched 3 way rocker. Is it possible, and what would be the best way to go about it? Thanks for any advice or input. Shawn

So you are saying the 3 position momentary "normally" controls ONE window up or down. With the other 3-way on (one way), the momentary controls linear actuator fwd & back, and... With that "other 3-way" on (the other way ), the momentary controls air bags up & down. If that's correct, then pending a logic check......: The latching 3 way could simply select which target is grounded; the momentary supplies power to all targets; and because the latching is centre-off, the ground selection is via 2 series SPDT relays with both 30-87a to the window motors; the relay's coils (85/86) to either "on" (actuator or bags) and its 87 to the target ground (actuator or bags).    And because of those "grounding" relays, that latching rocker can switch either hot or gnd (ie, to 86 or 85). So that's 2 SPDT relays assuming the momentary rocker handles full power. Otherwise add 2 more relays (SPST unless braking is required).

Correct, the momentary switches that are in there now control the windows up or down. The part that I still down understand is when the latching 3 way is off, to keep the windows working. When you say ground selection is via 2 series SPDT relays, do you mean 2 relays wired in series? I am not understanding that part. Also, if I use the relays as grounding, and the latched 3 way in is ON in either direction, does that stop the momentary from still operating the windows? Thanks Shawn

Ok - it's a bit late (here) and it may need a diagram... But Englishly speaking... The "normal" situation is windows. There are TWO series NC relays in the windows ground path. (IE - neither relay energised, windows motors are grounded.) If the latching on-off-on is in either ON position, it pulls in the respective relay above (hence breaking window ground) and connects/swaps its ground to the actuator else bags. Meanwhile, the momentary 3-position when ON provides power to all 3 (windows, actuators & bags) but only ONE of them is grounded.    Makes sense? (It does to me in Inglish, and head-logic etc, but I have yet to draw reality.... hence logic confirmation was sought. But I'm sure anyone hereon that sees the flaw will allow me to rope myself... (LOL!)). Like I wrote - it's late... And I experienced a strange phenomenon earlier... physical exertion!

I get what you are saying about the momentary supplying power to everything and use the relays to select which ones will see ground. Just can't grasp how it would need to be wired up. A diagram would be great. Will a simple 3 terminal latched rocker be ok for this, or will I need to use one with more terminals? Cause the way I see the latched switch being wired, is center terminal goes to ground. Then the outer 2 terminals would go to the ground for the relays to run the 2 different parts (actuators and bags). Or will I need another relay between the ground for the center terminal for the power window relays? I keep drawing out different configurations, but might be confusing myself even more. Maybe I am over thinking this and missing the simple way to do it. I think I will wait till you get some free time and some rest to draw up a diagram. Maybe that will make more sense to me. LOL. Thanks for the input and help. Shawn

Ok - it's rough and probably too big (I hate images that expand page margins!) And the catch is that without diodes (or other decoupling), whichever side is ON will also pass power through the other two loads and it's own unused grounded side... (just follow the example below...) EG - assume that instead of diodes, connections are straight thru: With "window" selected as shown (relays off), assume the top rocker is "UP". +12V then passes thru the RHS window motor and is grounded thru the relays. That's cool. But +12V also goes thru the RHS "Bags" and LHS Bags up to the LHS "Down" rail, the thru the LHS Window which is grounded. The same for the Actuator path.    And the same happens for any grounded "target" - ie, in parallel with the actuated & grounded target (window or bags or actuator; up or down etc) with be BOTH other circuits (in parallel) with the target's opposite non-actuated but grounded half. But the diagram is "conceptual" only - ie, it describes operation rather than implementation.... For example, if the "power" (upper) rocker can't handle the current, relays are required. If the devices are not separate +12V windings or terminals, then alternate switching is required (eg - if +12V & GND are reversed and not merely +12V as shown). And I do not like using diodes for "power" things - but up to 3A is usually ok. Above that, relay switching may be better. Before getting in to better design I figured I'd merely post the above.... Maybe 6 relays are required.... (SPDT else DPDT etc) And as I am about to order some FETs, I can't help but ponder... (Most prefer relays to "electronic components" like FETs & transistors. But with these MOSETS costing a mere $2.50 each; being the size of a thumbnail; capable of switching 60A-110A at kilo-Hz and merely requiring nano-Amps to turn on (with maybe 1 else 2 resistors per FET)... and silent operation....) Anyhow, what's the highest current involved? And are all devices "reversed" with polarity or an extra winding? (And which has which?)    PS - not that I like the energised relays above if left in bags or actuator position...

This rotary switch would allow the switches to be used for up to 6 different devices. 

2-Pole, 6-Position Rotary Switch

oldspark wrote: Ok - it's rough and probably too big (I hate images that expand page margins!) And the catch is that without diodes (or other decoupling), whichever side is ON will also pass power through the other two loads and it's own unused grounded side... (just follow the example below...) EG - assume that instead of diodes, connections are straight thru: With "window" selected as shown (relays off), assume the top rocker is "UP". +12V then passes thru the RHS window motor and is grounded thru the relays. That's cool. But +12V also goes thru the RHS "Bags" and LHS Bags up to the LHS "Down" rail, the thru the LHS Window which is grounded. The same for the Actuator path.    And the same happens for any grounded "target" - ie, in parallel with the actuated & grounded target (window or bags or actuator; up or down etc) with be BOTH other circuits (in parallel) with the target's opposite non-actuated but grounded half. But the diagram is "conceptual" only - ie, it describes operation rather than implementation.... For example, if the "power" (upper) rocker can't handle the current, relays are required. If the devices are not separate +12V windings or terminals, then alternate switching is required (eg - if +12V & GND are reversed and not merely +12V as shown). And I do not like using diodes for "power" things - but up to 3A is usually ok. Above that, relay switching may be better. Before getting in to better design I figured I'd merely post the above.... Maybe 6 relays are required.... (SPDT else DPDT etc) And as I am about to order some FETs, I can't help but ponder... (Most prefer relays to "electronic components" like FETs & transistors. But with these MOSETS costing a mere $2.50 each; being the size of a thumbnail; capable of switching 60A-110A at kilo-Hz and merely requiring nano-Amps to turn on (with maybe 1 else 2 resistors per FET)... and silent operation....) Anyhow, what's the highest current involved? And are all devices "reversed" with polarity or an extra winding? (And which has which?)    PS - not that I like the energised relays above if left in bags or actuator position...

Well the valves for the bag controls I do know are grounded already, and simply need a positive pulse to activate. So if the diagram you pictured will still have 12 volts going to it when its in another rocker position, the valves will be activated. Not that it matters, but we will be doing front and rear bags instead of RHS and LHS. The relays shown in your diagram, are those the ones that are already there to control the power windows, or are those additional? Reason being, I would like to keep from doing anything to those relays. Its actually a small control module he has installed. I am sure its just a box with relays in it, but don't want to affect the lifetime warranty of his module by tampering with it. And would also like them to be isolated with another relay to prevent causing damage to the switch. I am going to assume that all of the amperages will not be around 10-15 amps each direction on the switch (aside from the power windows), but can't be sure depending on load if he tries to run both switches at the same time. So just want to be safe and protect the window module and switches form anything I hook up, again to protect his warranty. I would prefer that the other devices not be seeing power all the time. Even if that means more relays. All feeds would be ignition based rather than 12 V constant, so not worried about them draining the car when its off, but I am with you about having all of them resting at 12 volts. I do know he is wanting to add the power windows to an alarm system as well, so don't want to run into an issue where he leaves the switch in the 1 or 3 position and activates his other devices instead of the windows. I would assume I can tie the alarm module down stream to the power windows and use a diode on the wires from the switch to the motor so it only operates the windows, no matter what position the switch is left in. As far as the the other electronics, that is way out of my league of understanding. LOL. I still have a tough time grasping the different configurations of relays to do what I want. Hence this posting. Haha. But if someone more knowledgeable than me wanted to build something to do this exact thing more efficiently, I would be willing to pay for the materials and their time. As long as its not going to be expensive. LOL. I was looking at relay control boards, but it seems all the ones I could find need to be operated from a PC/serial source. Again above my knowledge level. So does the added info affect the diagram greatly? I realize it probably adds twice the relays to the diagram. In my head, I was thinking of doing 3 relays coming off the latched rocker. When it was in postion 1, I would need to cut power to the other 2 relays, and vice versa for each position of the latched rocker. That way only the device selected would be getting power. I am not sure how to do that with relays. When one turns on, others shut off. Thanks greatly for the help. Seeing the diagram really cleared up what you were talking about. Shawn

The problem with the rotary switches is the size and the look. I was hoping to just add a 3 rocker to his setup to keep it all flowing as far as the look. And he would like something that is easily accessible, so mounting a rotary switch elsewhere would take away from that. But I do appreciate the help. Keep it coming. I am open to all sorts of ideas if we can come up with a solution that works for the customer as well. Shawn

Plus the rotary still needs some form of selection/activation button.... For the system above, interception is required on both hot & grounded sides - ie, the bag valves grounding needs to be cut & relayed. But the same occurs for anything that uses polarity changeover instead of an extra winding/terminal to reverse direction - eg, window up & down. (Most windows I know of are a two-wire motor whose polarity is simply reversed to change direction.) As to what the above relays are - that's up to you, though relays usually aren't required to switch other relays except for extra control logic or for high current relays (solenoids). But from what you say, it sounds like six relays are required where the rockers merely select which individual relay is activated at any time. The relay types depend on the connection required - ie, 2 SPDT for window polarity change over; 2 SPST for the air bags; and 2 whatever (SPST or SPDT) for the actuator. (In practice I'd use all SPDT - they are usually the same price, and can then be swapped if a NC contact (87a) burns out. IE - one size fits all; standard 15A or 30A SPDT "changeover" relays.) The only additional aspect is the window control. Since the device-selection rocker is 2-pole and not 3-pole, the window is selected by default (as in my diagram - the grounding relays) and selection of either of the others DESELECTS the window. That can be done with 2 diodes and an extra relay, or two extra relays. Your choice? It may be possible to reduce the number of relays depending on the actuator wiring (polarity changeover, or 2 wires plus hot or ground?), or if diodes etc are implemented (though I'd limit that to "logic" level only and use relays for all the power switching).