QTR-8RC components

I’m doing a group project for one of my university courses which will involve line following. We have £200 to spend and I really wanted to get hold of 4 of your QTR-8RC parts but unfortunately, we are only allowed to use parts from RS components and onecall.farnell for the finished machine.

I’ve looked at the circuit diagram you give in the documentation for the QTR-8RC:
but I can’t seem to find values for the IR LED’s, phototransistors or the MOSFET.
(I’m also not entirely sure if this diagram is for the 8RC or 8A)
I brought one of your sensors off your amazon store to have a look at it but I can’t see markings on the phototransistors or IR LED’s. At least not without taking them off the board.

Is there any chance you could give me the the part numbers or at least the values of the phototransistors/IR LED’s and the MOSFET? If we can design the circuit in Target then our technician will engrave us the PCB.


We do not have an Amazon store, and we have seen many counterfeits and knock-offs there, so we recommend getting our products directly from us or from an authorized distributor:


It looks like you are not clear on the distinction between the A and RC output types; you can get more info on those sensors in this QTR sensor app note. We do not disclose or commit to the exact parts we use for these sensors, but many manufacturers make similar components; here is a Digi-Key search for them:


For the MOSFET, just about any logic-level N-channel MOSFET that can handle your LED current should be good enough.


1 Like