Hi, hope someone here can help. Apologies in advance - I'm a complete novice when it comes to electronics and a bit unsure of correct terminology and meanings, be patient.

I am wanting to construct a piece of kit that will allow electrical pulses to pass through it up to a certain number per minute, below that all pulses pass through, above that only the amount wanted pass through. For example if I wanted a limit of 150 pulses per min then 100 would be allowed through but if there were 200 ppm only the 150 wanted would be allowed through. Make any sense? Does such a thing exist and what's it called?

Closest analagy I can think of would be a noise limiter in a nightclub where volume below a set limit is allowed unchanged, but exceeding that limit only allows up to the limit, the excess 'volume' is discarded.

The voltages(? watts,ohms,amps) would be very low, I don't know the correct term but I presume milliamps.

Is there an off the shelf device I can buy, or more preferably build myself. If the latter then how would I go about it, in laymans terms please, as simplified as possible. Or I'd be gratefull if someone could point me in the direction of a web link describing similar. Thanks.