Automatic Power On Off Switch

[penguintec]

Years ago I built an E-Bike, with an automatic On Off Switch.

It would switch on when it was moved, and it would switch off after being stationary for more than 10 seconds.

It was convenient.
Is anyone interested in the circuit ?.

I have been concentrating on electric boats these days, but If I have another bike it will definitely have this feature.

 

[Tench]

Yes, please post it up, surely it must have still had some current draw even when off though? or how did it power up, tilt switch?

 

[Matt Gruber]

my schwinn speedometer turns on/off by itself. battery lasted 7 years!
ebikes should all turn off by itself! on u can't forget, but off is another story.
as long as there is a bright LED for on, it is hard to miss.

 

[penguintec]

I've attached the schematic,

It draws very little current ~50uAmps when off, this is through R6 1Meg.

It uses the pulses or voltage from the wheel motor which acts as a generator when it is turned without power.

This turns on transistors Q1 and Q2.

While the wheel is turning, transistor Q3 is on, and this keeps the Relay ON to power the bike.
The relay could also be a Solid state relay.

After the bike is stopped, Q3 is held on by Capacitor C1 charging up.
Once this capacitor is charged up (10 seconds), Q3 switches off, the relay switches off and the circuit shuts down. Once again drawing just uAmps of current.


I will have to build it again to check it works but you get the idea.

It was handy not having to worry about switching off the bike.
(I also had a high-brightness blue LED that pointed to the ground like the cars in 'Need for speed')