I am a keen cyclist and have a front light which is powered by a dynamo hub. There is an output from the front light which can be used to power a rear light.
There are some fancy lights on the market which include brake lights. A brake light can be very useful if you are in a large group of cyclists.
When you slow down, the dynamo produces less power. The rear light detects this power drop and activates the brake light.
I am intending to build my own back light which will include a brake light but cannot figure out a way to activate the brake lights when the power drops.
If I use a capacitor which will be charged up to the supply voltage, then when I slow down the voltage in the capacitor will be greater than the supply voltage. I want to use this voltage difference to activate a transistor to power the break light LEDs. But I do not know how to do it.
Do I need to use some form of comparator (about which I know nothing), or is there a another option?
Any advice would be appreciated.
There are some fancy lights on the market which include brake lights. A brake light can be very useful if you are in a large group of cyclists.
When you slow down, the dynamo produces less power. The rear light detects this power drop and activates the brake light.
I am intending to build my own back light which will include a brake light but cannot figure out a way to activate the brake lights when the power drops.
If I use a capacitor which will be charged up to the supply voltage, then when I slow down the voltage in the capacitor will be greater than the supply voltage. I want to use this voltage difference to activate a transistor to power the break light LEDs. But I do not know how to do it.
Do I need to use some form of comparator (about which I know nothing), or is there a another option?
Any advice would be appreciated.