need advice on adding a switch

Hello, need some simple help from you guys. Looked at a lot, this relay diagram looks the closest. https://www.the12volt.com/relays/relaydiagram49.html

I just acquired a used VA model Invacare M93 Powerchair for getting around. It came with some powered options, one which is missing some pieces. On the joystick it has two on-off-on spring loaded toggles. Each has three wires coming down to powerbase. Middle wire looks like a shield, meaning no jacket on it but it connected to either A or C completes separate circuits. The working one operates a seat lift, wire disappears into actuator, no clue as to what happens inside. The non working one on the footrest is missing any type of controls between the end of switch wire and the actuator. The actuator works on bench, so I need to connect it back up again. Looking at the diagram where does that middle wire land? If it is just a ground, can I skip the relays and wire like the seat lift?

-------------
Thx, Bob

Sorry for the delay...

In in that relaydiagram49 Door Locks - Actuators / Reverse Polarity - Positive Switch/Trigger the middle wire would be to +12V which is then switched to either "(+) from switch" side.

It is easily converted to a grounding switch by connecting 86 of both relays to +12V and taking each 85 to the switch outputs - ie as per relaydiagram4 & relaydiagram48 (which are both the same but with the target actuator shown or not shown).


Whether the relays are needed or not depends on the actuator. The relays are needed for the polarity reversal on 2-wire actuators but not 3-wire actuators assuming they are a bi-winding type (with common center tap) AND that the switch handles the current.

I usually prefer relays for handling motors and actuators due to their inductive spikes (which arc and wear raw switches without capacitive snuffers) if not their Amperage requirement. (I don't like switching more than a few Amps thru switches.)
Usually relays are easier and cheaper to replace than switches, plus there are far more low current switches (or circuits) to choose from than high current switches. (Plus cheaper, & thinner wiring required, lower target load voltage drops, etc.)
And in this case the relays (coils) only draw power when being actuated so I see no issues with any "extra" 60-250mA coil draw.

Hey, thanks for great advice. It is a two wire actuator. I've ordered a pair of relays and will eagerly start play when they arrive. Went to ISS the wheelchair show in Nashville this week, glad to be back home to my own space! I went out and hugged my garage stuff, momma didn't get it, she got a glass of wine instead!

Ya'll have a great weekend, Bob

-------------
Thx, Bob

Glad to see your Momma's doing the drinking while you're doing the driving! (Ha ha)
Of course I'm obligated to say that in support of our Laws etc. (I prefer the act - or drink - responsibly approach; noting that not all realise (yet) what responsibility entails).

Tho on a serious note, there have been cases here in Australia where wheelchairers have been booked for "drunk driving" aka DUI. (Probably by the same group of ignorants that thing that Seeing Eye and Companion canines are animals and hence not allowed in cabs, restaurants, etc etc. Being booked for dangerous driving or vicious or unhygienic animals is one thing, BUT...)


Let us know if we can help further.