Completely Analog Circuit for playing Ping Pong on Oscilloscope

raymondtco said:

Hi All,

I am building a Completely Analog Circuit for playing Ping Pong on Oscilloscope (Tennis for two) from scratch (resistors, capacitors, op amps, and JFETs).

I am stuck on the fact that, since I want to include the gravity by two integrators (to generate the 1/2 gt^2 term in kinematic equation), the capacitors in the integrators will be fully charged after a period of time.

Do you guys have any idea how to go about this issue by using resistors, capacitors, op amps, and JFETs?

I found this schematic but I can't understand some of the notations, such as a bar wound by a wire (inductor?) and a line sandwiched by two arrows.

Tennis For Two


Thanks a lot!!

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Mikebits said:

Wow that is old. So what are the symbols that look like buffers?

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Mikebits said:

I thought they did not have op amps in 1959? Aside from the tube version...

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Had to check, FYI
Operational amplifier - Wikipedia, the free encyclopedia

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Pommie said:

I was -1 at the time so I've not got a clue. However, to make an integrator without an opamp would be pretty tricky. So they must have had them even if they were fabricated from individual components.

Mike.

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ericgibbs said:

hi Mike,
At British Steel we used to make analog computers using either early transistors or valves.

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Nigel Goodwin said:

Which of course is where opamps came from, as the central part of analogue computers - long before IC's.

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Mikebits said:

I had to look up analog, or analogue computers. Did you know the slide rule was considered a analog computer.

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Mikebits said:

I had to look up analog, or analogue computers. Did you know the slide rule was considered a analog computer.

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