Aversive stimulus detector

[snipervvolf]

Good afternoon!
I'm a student studying behavioral biology and I am in the process of designing an automated apparatus for my research on aversive conditioning in honey bees.

I am trying to power a relay from shock traveling through a bee. I would like to record how often and at what time a bee is receiving shock during a five minute trial session. These will be very quick and very light pulses that will need to trigger a relay to communicate with my interface for real-time recording of aversive stimuli application to the subject. Minimizing delay and maintaining chronological acuity is paramount.

I was able to devise a circuit using a 7805 and a 741 that worked somewhat, however, it was immensely unstable and unreliable. My power source will be an ac-dc adapter and the range of input voltages will be from 5v-12v.

I just need a binary output of when the bee receives shock, nothing really fancy or anything like that. It just needs to work at 5-12v if that is possible.

Would anyone be willing to assist with this circuit design? I'm not even sure where to start as far as adapting another circuit design to facilitate my needs for this circuit's application.

Thank you so much for any direction you may be able to provide!

Best wishes,
~Chris

 

[Sceadwian]

Define "very quick" Relays aren't generally suited for 'very quick' unless it's a reed relay, and you have contact bounce to deal with, a transistor in place of the relay would be far simpler. Are you opposed to using a micro controller this can be done trivially using one. I'm curious as to how your 7805 and 731 circuit was constructed because counting pulses isn't exactly something you can do with a voltage regulator and an opamp.

 

[snipervvolf]

Thank you for the reply!

Unfortunately I do not have access to a PICkit or micro controller. I have explored using micro controllers but I would like to exhaust other options before investing time learning to program it and the money to buy the required tools.
I would not be opposed to using a transistor but would I be able to deliver a steady 4.5v if powered by 5-12v? The interface I am using is very finicky and fragile in that regard. I am not at all adequately versed in how these thing work to really understand the differences.

By quick I mean being able to detect an insect running across an electrified grate. The interface I am using has a debounce of 30 ms so anything shorter than that really won't matter.

I just need to make sure my output voltage remains steady (4.5v) regardless of the voltage powering the circuit (5-12v depending on the variables manipulated in the trial).

As far as the opamp 7805 mess, it was equivilant to using a hammer to drive a screw into a block of wood. It worked but was nothing but brute force and obviously the wrong tool for the job.

 

[Sceadwian]

Why do you not have access to a micro controller, and if not what DO you have access to? A list of parts that you may be able to use would help.

I think you need to clarify your exact needs here as in your second post you mention 4.5 volts is critical which isn't even mentioned in your first post so obviously there are some problems with you state clearing what you have to start with what you have to end up with in detail.

We can't provide you with useful information until we get a total picture of what's going on. Take some serious time in your next reply to fully explain in detail what is going on and what you need to accomplish.