Forums » General Electronics Discussion

Hi My First Post. I have just spent three days looking for answers to solve my two seperate problems. They are for my daughters Electric Trike.

1. On the trike is an resettable (self Healing ) thermal fuse, but she needs to know when the fuse has been tripped (it only gets tripped mainly because when she crashes into something she forgets to take her foot of the pedal) So I need A Nice big bright LED to come on when the fuse is tripped. I can take the power from the battery before the fuse a s a permanent source But I only need the light to come on when there is no power on the other side of the fuse. Summary fuse gone - no power - light comes on

2. My second circuit I Am have trouble with is making some brake lights that go off when the power is applied this circuit is slightly different in the fact that I need the lights to go off when a 12v power supply is detected. There is a wire int the front of the bike that lights the headlights when the trike is moving, but headlights go off when the bike stop. so I want a reverse circuit for this.

I have tried my self, and much to my daughters delight I have uprated to daft headlight bulbs to bright LEDS and it looks so cool. She now has an indicator circuit for left and right indicators, that flash authentic and even make that car tick tock sound you hear, and a hazard light circuit with flashing hazard button using 555 timers to get the sound and flash rate just right.

Heres to your kind help in advance.

Many Thanks.

Rik, (And daughter)

@RikB,

Welcome to CL.

1) https://www.circuitlab.com/circuit/zyfkyb/blown-fuse-indicator-01/

2) https://www.circuitlab.com/circuit/v585mp/kids-electric-bike-brake-lights-01/

connect the LED (with a series resistor) paralell to the fuse - done Unless the trike has a very low consumption electronc (without the motors of course) the LED should be on as soon as you turn the (ignition) key on and the fuse has tripped.

@signality

Thank you so much for your help. Have ordered the mosfets this morning (the only thing I don't have in my basic kit)

Can't wait to start putting it together for my daughter.

Thank you again.

You'll have to verify the LED series resistor values to suit the currents and forward voltage drops of the LEDs you've chosen.

You may therefore also have to check the MOSFET Id ratings.