Re: Need a transistor-less, IC-less photocell circuit
Posted: Sun Nov 15, 2009 7:16 pm
Thanks for all the help! Leaning towards the many-CdS-cells-in-parallel route.
One unfortunate thing; due to "rules lawyers", everything is spelled out to an extreme-- even commas matter. Also, since I used to be a National Supervisor for this very event, anything my kids do is scrutinied to an extreme, which means I have to be very careful as to what I approve. Unlike other coaches, I don't touch their stuff (proof: look at their soldering, er, welding), so it all needs to be do-able.
Okay, here are all the applicable rules:
10V dc max, source AND components (it took two years, but they finally banned our use of choppers)
No diodes, transistors, microprocessors or other solid state, and no 'modules" containing such.
No motors may be running before the device starts.
"Activate a photocell which will provide the power to operate a motor, which leads to the next action." [this is the actual task]
+++++++
So, any "sticky wickets" that might crop up: the "no motors running beforehand" and a requirement that all steps be in sequential order A -> B -> C ->D etc., means that this thing has to turn the motor ON.
Also, the motor has to do "something" to start the next step, which means that, with a low-current motor, it can't be required to do much, like push a ping-pong ball.
Not sure if "provide the power to operate" means a relay can't be used. There's been no "chat" about it amongst the event supervisors yet (I run the event in one state). Personally, I say they CAN be used.
Looking for CD spindle motors as I type,
Yerry
One unfortunate thing; due to "rules lawyers", everything is spelled out to an extreme-- even commas matter. Also, since I used to be a National Supervisor for this very event, anything my kids do is scrutinied to an extreme, which means I have to be very careful as to what I approve. Unlike other coaches, I don't touch their stuff (proof: look at their soldering, er, welding), so it all needs to be do-able.
Okay, here are all the applicable rules:
10V dc max, source AND components (it took two years, but they finally banned our use of choppers)
No diodes, transistors, microprocessors or other solid state, and no 'modules" containing such.
No motors may be running before the device starts.
"Activate a photocell which will provide the power to operate a motor, which leads to the next action." [this is the actual task]
+++++++
So, any "sticky wickets" that might crop up: the "no motors running beforehand" and a requirement that all steps be in sequential order A -> B -> C ->D etc., means that this thing has to turn the motor ON.
Also, the motor has to do "something" to start the next step, which means that, with a low-current motor, it can't be required to do much, like push a ping-pong ball.
Not sure if "provide the power to operate" means a relay can't be used. There's been no "chat" about it amongst the event supervisors yet (I run the event in one state). Personally, I say they CAN be used.
Looking for CD spindle motors as I type,
Yerry