| ??? 01/17/05 01:35 Read: times |
#85065 - re: Source Impedance and driver types Responding to: ???'s previous message |
Raghunathan said:
1. In a mains operated unit, whether the output is referenced to mains ground or floating ( would a simple ohmic value check between the -ve terminal of the output and the PE pin suffice ? ) Unless it's isolated with a transformer, you must assume that it's referenced to the local ground, which of course must be connected to the mains ground. If the output is differential, then the + signal is referenced to the - signal. However, both of course remain within the rails of the driver. 2. Source impedance. This is the real problem- you have no idea unless the manufacturer specifies - is there any way to find this out ? Call the vendor and ask? I'm sure they'll tell you. Otherwise, simply open the box and look. I would expect that most outputs are driven by op-amps, so you can expect a very low output impedance. Sometimes there's a "build-out" resistor in series with the op-amp. This resistor serves two purposes. One, it keeps the op-amp from self-destruction if you short the output to ground. Two, it sets the output impedance. if it's not an op-amp output, then you really have to contact the vendor and find out what the transducer really looks like and what it expects to see. -a |
| Topic | Author | Date |
| Source Impedance | 01/01/70 00:00 | |
| Re | 01/01/70 00:00 | |
| Impedance measurement | 01/01/70 00:00 | |
| Being more concrete | 01/01/70 00:00 | |
| What about my Rogowski Coils. | 01/01/70 00:00 | |
| Already answered in detail! | 01/01/70 00:00 | |
| Re: ' Detailed Answer' | 01/01/70 00:00 | |
| Bridge | 01/01/70 00:00 | |
| What Bridge, | 01/01/70 00:00 | |
| bridge | 01/01/70 00:00 | |
| and ... | 01/01/70 00:00 | |
| Using an OPamp | 01/01/70 00:00 | |
| Using OpAmp | 01/01/70 00:00 | |
| Some disadvantages | 01/01/70 00:00 | |
| Correct formula | 01/01/70 00:00 | |
| Thanks Kai, | 01/01/70 00:00 | |
| LCR meters quite common | 01/01/70 00:00 | |
Re: LCR Meter. | 01/01/70 00:00 | |
| Resonant coupling... | 01/01/70 00:00 | |
| Sorry! | 01/01/70 00:00 | |
| Go with the rule of Thumb | 01/01/70 00:00 | |
| No more than about 10kOhm | 01/01/70 00:00 | |
| Line drops | 01/01/70 00:00 | |
| Thicker cable | 01/01/70 00:00 | |
| Freq domain analysis | 01/01/70 00:00 | |
| re: Source Impedance and driver types | 01/01/70 00:00 | |
| universal solution | 01/01/70 00:00 | |
| Thanks .... | 01/01/70 00:00 |