Water injection and racing & more

[Walter Petermann]

Matthew Harding wrote:
> 
  .......
> I need something that will accept an input voltage between 0 and 5 V...
> and a clock pulse
> 
> and depending on the input voltage, output a pulse who's width varies
> linearly...
> 
> have i explained this right
> 
> so say there's a clock pulse, and the input voltage is 0V, I want a puls of
> 2ms to be the output....
> 
> if there;s a clock pulse, and the input voltage is 5V, I want a pulse of
> 6ms to be output....
> 
> 5V                                     *
>                                     *
> 4V                               *
>                               *
> 3V                         *
>                         *
> 2V                   *
>                   *
> 1V             *
>             *
> 0V       *
> 
>         2ms     3ms     4ms     5ms     6ms
> 
> bit like that.....
> 
> can anyone help me?  I do not want to use any microprocessors in the
> design....
> 
> thanks

Mathew,
If you are handy with electronics you could try a timer chip
like Motorola MC1455/1555. This has a trigger input (for
your clock) and a threshold input to which you would connect
your variable voltage. The output can sink up to 200ma,
enough to turn on an automotive relay (about 80 ohm coil)
with a supply of 12v. Although it would be best to use an
external transistor for the relay. 

 Walter