amplifier circuit.

[mrod424]

Hello. I am new to this forum and have very little circuit design experience.

I need to build a circuit that accepts a TTL signal and amplifies the input voltage ( 5 volts I believe) to +/- 10 volts. The circuit output then goes to a ThorLABS high voltage amplifier (HVA) that accepts +/- 10 volts input.

Basically I need to send a TTL signal from my computer using LabVIEW through a virtual USB port or an RS-232 serial port (not sure which of these is a better option). I am assuming these two options are TTL compatible in some way (do I need some circuitry?)

Then I guess I need an op-amp to amplify the signal from 0-5 volts to +/- 10 volts. And output to the HVA with a BNC connector.

I was wondering if this is as simple as I just put it or am I missing any crucial details. Anyone have any advice or know of any threads with similar circuit design/implementation.

Thanks.

 

[alec_t]

Perhaps the MAX232 chip will meet your needs?

 

[ccurtis]

If you send the signal out through your computer's serial port (assuming it has one) on the RTS, or the DTR, output pin, it might directly generate a ±10V signal. You can measure the voltage at the RTS and DTR output pins on the serial port connector to find out. When idle, and the serial port is enabled, the voltage will be +V or -V. (±5 V, ±10 V, ±12 V, and ±15 V levels are commonly seen.) If the voltage is what you want, you can use LabView to easily toggle those outputs between the +V and -V states at will.

If you find that the voltage is ±5 V, you could toggle the RTS and DTR into opposite states simultaneously and take the voltage across those two pins to get ±10 V. If you find the voltage is higher than ±10 V, you can use resistors to divide the voltage down to a lower level, or use a pair of 10V zener diodes and series resistors to clamp the voltage to ±10 V.

 

[mrod424]

Cool. Thank you for your responses. I will look into the RTS and DTR output pins. All the computer's serial ports are being used at the moment but I plan on purchasing an expansion slot for an additional RS-232 serial port.