Using a signal generator as a voltage sink

[BStanley346]

I am trying to reverse engineer the expected frequency for a few gauges in my car. The cluster computer is fed 12VDC and circuits are grounded via sensors at random frequencies which are interpreted by the computer and displayed. I have a spare gauge cluster, power supply, and signal generator and I am wondering if the signal generator can be used as a voltage sink to trigger the logic? Would I need to set up a high-frequency relay of some sort or is this something that a signal generator should be able to handle? I know that these signals are typically tied straight to ground so there would be built-in resistors to keep the current low but I have no idea what the expected draw would be. I am using a Koolertron 60MHz signal generator (can be found here for more data https://www.amazon.com/gp/product/B073P6TKQC/ref=ppx_yo_dt_b_asin_title_o00_s01?ie=UTF8&psc=1).

Thank you in advance.

[WattsThat]

Signal generators are voltage sourcing devices, it appears the device in question can generate up to 20 volts peak to peak. That is usually into 50 ohms but who knows, the specs are a bit dodgy.

If the gauge supplies voltage that needs to be pulled to ground to generate a low pulse, that can be achieved with an NPN transistor with it’s base driven through a resistor from the generator output.

It would be most useful to scope what’s going on in a working system/car to know what amplitude and frequency signals are needed.

[radiolistener]

Yes, you can use it. But you're needs to use CMOS waveform, because standard Sine/Square/Ramp/etc waveforms use oscillation around zero.

For example if you use Sine waveform and setup amplitude 5 Vpk, you will get voltage change from -5 Vpk to +5 Vpk. -5 Vpk is not safe for logic input and even can destroy it. This is why you need to use CMOS wavform, which produce square wave above zero (for amplitude 5 Vpk it will be from 0 Vpk to 5 Vpk).

Also you're needs to check required logic volatage and setup amplitude properly.

[james_s]

If I understand what you're trying to do, all you need is a NPN transistor and base resistor or N channel mosfet. Drive the base/gate with the function generator, ground the emitter/drain and connect the collector/source to your cluster. When the output of the signal generator goes high, the transistor will switch on and pull the line to ground.