I'm not comprehending the CT-22 display wiring on a fundamental level

[okie]

I'm trying to install a CT-22 display with a SVMC 72150 and QS 205.

My understanding going into this was that the display didn't actually control any controller settings, but rather you just ran your wires through its LEDs and it passively showed what mode you were in.

But looking at the wiring diagrams, it seems like the display is actually telling the controller what mode you're in. Like instead of connecting my 3 speed switch to my controller, it's looking like I would connect that switch to the display only.

What I'm not understanding is how the display would communicate with the controller. Does it do it through the hall meter somehow?

 

[E-HP]

The CT-22 is a display, period. It's an interesting display that I've recently learned to appreciate. The main function is the speedometer, which is cool, since it takes any pulsed signal and just applies a factor to it to determine speed. No magnet or pole counts, or wheel size, it just takes whatever pulse, and a divisor that the user sets, to compute the speed; very cool. All of the other functions are just displaying graphically, the status of lights or your three speed switch, however, you may need to do something creative to get the 12V signals the display needs, from the source of those signals (if your lighting system is already 12V, it makes it easier. For the 3 speed switch, it looks like you'd need a double pole vs single pole switch, to send the 12V signal to the display).

I don't have the display, but have been looking at the available manuals and posts so I can add a section to my newbie FAQ, since a lot of folks seem to need a speedo for controllers that don't support a display.

 

[AGS]

The wiring diagrams that I have seen for the CT22 display only have LEDs for the 3 speed switch. The switch itself needs to control the controller.

But if you want a dashboard display that lights a led to show which speed you are in then the LEDs in the display need to be switched as well.

 

[okie]

The CT-22 is a display, period. It's an interesting display that I've recently learned to appreciate. The main function is the speedometer, which is cool, since it takes any pulsed signal and just applies a factor to it to determine speed. No magnet or pole counts, or wheel size, it just takes whatever pulse, and a divisor that the user sets, to compute the speed; very cool. All of the other functions are just displaying graphically, the status of lights or your three speed switch, however, you may need to do something creative to get the 12V signals the display needs, from the source of those signals (if your lighting system is already 12V, it makes it easier. For the 3 speed switch, it looks like you'd need a double pole vs single pole switch, to send the 12V signal to the display).

I don't have the display, but have been looking at the available manuals and posts so I can add a section to my newbie FAQ, since a lot of folks seem to need a speedo for controllers that don't support a display.

The wiring diagrams that I have seen for the CT22 display only have LEDs for the 3 speed switch. The switch itself needs to control the controller.

But if you want a dashboard display that lights a led to show which speed you are in then the LEDs in the display need to be switched as well.


View attachment 357410

So somehow the 3 speed wires from the switch have to run through the display and then into the controller? I'm having trouble envisioning how that could work.

 

[E-HP]

The three speed switch uses 2 signal wires and a ground, so the switch won't have 12V to feed to the display. You'll need to use at least a double pole switch, with one pole doing the regular 3 speed functions (signal 1 to ground, open, signal 2 to ground), with the other poll providing 12V to the display depending on the switch position. I think it will be a PIA, but if you were OK with low and high turning on the respective display LEDs, and medium/normal not lighting the middle LED, that would simplify the circuit (12V to the middle pin, high and low going to the other two terminals).

https://www.amazon.com/QTEATAK-Position-Rocker-Toggle-Switch/dp/B0BHDHRQX7

 

[okie]

The three speed switch uses 2 signal wires and a ground, so the switch won't have 12V to feed to the display. You'll need to use at least a double pole switch, with one pole doing the regular 3 speed functions (signal 1 to ground, open, signal 2 to ground), with the other poll providing 12V to the display depending on the switch position. I think it will be a PIA, but if you were OK with low and high turning on the respective display LEDs, and medium/normal not lighting the middle LED, that would simplify the circuit (12V to the middle pin, high and low going to the other two terminals).

https://www.amazon.com/QTEATAK-Position-Rocker-Toggle-Switch/dp/B0BHDHRQX7

Oh okay so what you're saying is I wouldn't be able to use the 3 speed handlebar switches off Amazon. As in I would have to homebrew my own switch?

 

[E-HP]

Oh okay so what you're saying is I wouldn't be able to use the 3 speed handlebar switches off Amazon. As in I would have to homebrew my own switch?

Yes, although you may be able to use the Amazon switch with some relays; I just haven't thought that through, plus I skipped having coffee today. In any case, you can't connect the switch directly to the display.

 

[okie]

Yes, although you may be able to use the Amazon switch with some relays; I just haven't thought that through, plus I skipped having coffee today. In any case, you can't connect the switch directly to the display.

I think I understand. Thank you for all your help!