A little electronical help.

[LazyDev]

I have a Roomba 530. I've modded the bumper sensor and rid the IR emitter and transistor and replaced with a micro switch and also created "Full Bin" sensor using an IR photo transistor  Problem is, I need the photo transistor to be always on with no light and switch off when their is light, but don't know what the name of that sensor is.

 

Also, what's an alternative to an LED? An ultra bright 20K luminus LED or a laser pen?

 

Basically, what's the alternative to a photo transistor? (Always on, light switches it off)

 

I also need a resistor that does 12 volts to 5 volts.

 

 

[Samdb]

A NOT gate will sort out the always on sensor, an alternative to an LED? What do you mean by this? What is it that you need the voltage decreasing for? What is its max current?

[Samdb]

If you use this high intensity LED, you will need a 300 ohm resistor.

http://www.rapidonline.com/electronic-components/kingbright-high-intensity-led-10mm-64870/

If you intend to use an ultra bright LED, you will need a 260 ohm resistor.

http://www.rapidonline.com/electronic-components/kingbright-ultrabright-led-5mm-77694/

[LazyDev]

I joined two 270ohm resistors and it did the trick.

Next question.

The brush motor isn't powering on. I've put a multimeter on the circuit and it shows 15 Volts. I've tried other motors on that circuit but that doesn't power the motors on.

Basically Their's 15 volts, but it's like a dead circuit when you attach something to it. Even LED on the 15 volt circuit doesn't power up. Help?

Could the PCB (Motherboard) of the robot be dead?