Voltage Controlled Switch

[brighteyes]

Guys

Can anyone help with a small project on a motorbike

Guys

Was wondering if someone could help me with a small project.

I'm after something that will allow me to control (open or close) an output based on an input voltage taken from a Gear Position sensor on a motorcycle (0v to 5v) i.e. neutal=0.5v, 1st=1.1v, 2nd=2v, 3rd=2.7v, 4th=3.5v, 5th=4.1v and 6th=4.7v)
Otherwards turn on when voltage is between 0V and 3V and off up to 5V.
(On for 1st, 2nd & 3rd and off on 4th, 5th and 6th)

I want this to act as a circuit breaker with the ability to control on/off per gear and was planning to break a signal wire.

Any idea's?

Cheers

Pete

[Alex Tsekenis]

You can use a comparator to sense when the voltage has exceeded say 3.2V, and then the output from that will drive a relay, possibly via a transistor.

Have a look here

http://home.cogeco.ca/~rpaisley4/Comparators.html

Let us know if you need help designing it.

[Hero999]

You beat me to it Alex.

I'd recommend the LM311 because it can directly control a small relay.

[Alex Tsekenis]

You beat me to it Alex.

Sorry, I know it is important to you.  :P ;D

[brighteyes]

Thanks Alex and Hero999  :)

I'll have a good look through the pdf's and come back to you sp thanks very much!
We have a mechanical device that we want to switch off on 4th, 5th and 6th so basically the output is to open/close the circuit or simply drive a relay which I can place in between one of the circuit wires.

Do you know of any suitable relays and if it would be possible to use a variable resistor to control the voltage range that is permitted? i.e. to permitt 3rd gear

In fact do you know if I can buy the whole solution from somewhere lol

[Hero999]

I doubt you can buy the whole thing pre-made unless you're willing to pay someone lots of money to design it for you.

Any relay can be connected to a comparator which will allow a variable resistor to be used to adjust the threshold; read the articles linked above.

[brighteyes]

If someone sends me an offer I would certainly consider it lol

The ability to open/close a relay based on input voltage with adjustable resistance to change the voltage permitted which will be 0v to 5v.

Anyone want to take on the challenge? Would pay via Paypal etc

:)

[Hero999]

In order to get someone to do it for you, you need a proper specification first.

What are you going to be powering it from? A 5V regulated supply, a 12V bike electrical system?

How much current does the relay need to switch? What is it switching?

What value is the adjustable resistance? Or do you just want a potentiometer and you don't care what the value is. If so can it be board mounted? Does it have to have a proper knob or is a trimmer which can only be adjusted with a screwdriver good enough?

What's the expected operating temperature range?

What's the IP rating i.e. does it have to be waterproof or dust/oil proof?

Is going to be subject to mechanical vibration?

These are the sorts of questions you need to answer before selecting a product or getting it designed for you. I could design something that would fulfil all the criteria you've listed above but might not meet your needs because there's some requirement you may have that I don't know about. For example I could design it to be run from 5V, then you fry it by connecting it to 12V or it breaks in a few months when water corrodes the circuit board.

Where do you live?

If you're based in the UK, I'll do it providing you give me a good specification, pay me a reasonable price and pick it up from my house.