relay question

[Mr Charles]

I am extensively upgrading a 4 I have had and flown for years and have a particular thing I am wanting to accomplish, but unsure of the method. I am familiar with basic relays and wiring, but I am not an electronics whiz!
I have a homebrew smoke system that I previously operated via a toggle on the panel. I am now installing a Mac stick grip and have one button unused. I would like to utilize the single normally open momentary contact button to both turn on and turn off my smoke pump. I understand a relay and toggle, and assume there is probably a "latching" relay that I could use with the momentary contact of the switch to turn on the pump...but how can I do this to also turn the pump back off with a momentary contact push of the same button??
I would appreciate any ideas/advice from the experts!!!
Thanks,
Charles

[Mike S]

Look for an "impulse" relay. Also, "step" relay.

[Mich48041]

eBay item number:292517299208
or search eBay for Flip-Flop Latch Relay
Requires 5vdc for logic circuit.
Output relay can switch 12 volt load.
Costs less than $5 from U.S. supplier.
Half price direct from China but 1 month shipping.

[vlittle]

Charles, please also consider putting an Arm/Disarm toggle switch in the system to unambigously cut power in an emergency. You don't want to be pumping oil in the event of a fire.

V

[Mr Charles]

Thanks for suggestions...I have researched the three options mentioned but am not knowledgeable enough to make a choice yet. Can anyone clarify any major pros/cons of any of the three mentioned types? I am thinking the flip flop would be light and simple...assume I can power it from the 5v output of the Skyview?

Could someone please sketch a simple wiring diagram for installation of same?

Vern, great point! I actually already have the wiring/panel set up for that part of it...a "master breaker switch" for smoke, with a small LED pilot for indication!

Charles

[Mich48041]

Here is a picture showing how to wire the flip flop relay.
Vcc is +5vdc
Momentarily applying ground to the input terminal toggles the output relay.
Connect 12 volts to the relay COM terminal.
Connect the relay N.O. terminal to the load.
Of course the load also has a ground wire connected to it.
Advantages of this module are low cost and low control current which is good for the stick switch.
A disadvantage is that it requires 5vdc for the control circuit.
_
Another option is an impulse relay.
It costs between $50 and $70. It is electro-mechanical, not solid state. The control circuit requires more current.
What is the rating of the stick switch?
The impulse relay coil should have an arc suppression diode across it
with the banded end connected to positive.

[Mich48041]

According to the Skyview installation manual, the +5 volts DC Auxiliary Power
Output is Limited to 300 mA by internal self-resetting fuse. Part of that 300 mA
supply might be used for various sensors. Who knows what the flip-flop module requires?

[Mr Charles]

Joe, the pic didn't post, but I may have figured that part out as I found one on fleabay that had the diagram posted...along with your description that part sounds pretty straightforward.
The switch rating is 5 amp, and the wire is a 26 guage. I like the idea of solid state I think. Sounds lighter and more simple. Maybe more reliable? Not concerned about pricing either way...
Good point about current needs of controller....The controller is dirt cheap, so I ordered one and I assume I can do a bench test and check the current draw...
Not sure what my total draw for sensors will be in my Skyview system...it will be a standard install for a IO-360, and the autopilot servos, and a Ray Allen trip position sensor. Am I forgetting anything for 5v needs?? But I suppose if necessary there are probably 12 to 5v supply transformers available? Is that what I would need to supply the 5v power if the Skyview system doesn't have enough capacity?

[Mich48041]

Your Skyview 5vdc supply might be powering a manifold pressure sensor, fuel pressure sensor and trim position pot. It seems that the relay coil is powered by 5VDC. It is a good idea to measure the current draw on the work bench. If it draws too much, a 12 volt to 5 volt DC to DC converter is needed.
Try this WEBSITE for a picture of the flip flop relay.
Your 5 amp rated stick switch should be able to handle the electro-mechanical impulse relay coil (with diode) OK.

[charosenz]

Originally Posted by Mr Charles

I am extensively upgrading a 4 I have had and flown for years and have a particular thing I am wanting to accomplish, but unsure of the method. I am familiar with basic relays and wiring, but I am not an electronics whiz!
I have a homebrew smoke system that I previously operated via a toggle on the panel. I am now installing a Mac stick grip and have one button unused. I would like to utilize the single normally open momentary contact button to both turn on and turn off my smoke pump. I understand a relay and toggle, and assume there is probably a "latching" relay that I could use with the momentary contact of the switch to turn on the pump...but how can I do this to also turn the pump back off with a momentary contact push of the same button??
I would appreciate any ideas/advice from the experts!!!
Thanks,
Charles

I just built my own relays. I found the latching coils more trouble than they were worth. As you have to "reset them"

I did a proof of concept using off the shelf parts and it worked great. It is crude. Here are some pics.



The yellow wires go to the motor. The green goes to the respective up and down ground switch. Re+/Blk_. Very simple and very inexpensive. But crude.

Here is the business side of things I just hotgolued them to thin lexan.



I decided to create a custom PCB that had better components and a smaller footprint. It is a 5 amp board with reverse polarity protection. They are being manufactured now.



If you have questions, you and PM me or if the OP is ok with it we can talk more about it on this thread. His call.

Charlie Rosenzweig