80Views4Replies

Author Options:

how to use LDR as a relay for RC car to increase voltage to motor Answered

Hi there, 
I would like to know more about how LDR's work, its quite difficult to source 3 volt relays in South Africa, so I had an Epiphany, why not use 2x  LDR 1x for Forward and 1x for Reverse on an RC car, I don't know much about how responsive the solution is, how many seconds or milliseconds delay  there is? Does it work like a switch?  would it be a viable option on an RC car?
I'm sure this could apply to little 3 volt RC cars upwards, I know brushless is the way to go, however this would indeed be a great learning experience. 

kindest Regards,
Lee Reddy. 

Discussions

0
None
Downunder35m

2 years ago

Unless you mean something different then a LDR is a light sensitive resistor...
And instead of a relay you could use a simple transistor with a protection diode.

0
None
Leereddy1818Downunder35m

Reply 2 years ago

I haven't worked with transistors, with the method that you have proposed... will it route at least 4.5 volts to the motor ? obviously it would require two circuits one for forward and the other for reverse, so the question is, does it act as a replacement of a relay?

0
None
Downunder35mLeereddy1818

Reply 2 years ago

If you check Google for "transistor motor directional control" or "bidirectional dc motor control" you should find plenty of examples including some words of explanation on how it works.