AVO Model 8 Mk 7 question

[Chris_A]

Hi,

I am trying to find out what current you get across the terminals of an AVO Model 8 Mk 7 in the resistance x1 ohm range.

I have checked a Mk 6 and get 73.5mA, I am assuming that the a Mk 7 would be similar but don't have both circuits so can't confirm.

If anyone has a Mk 7 handy and could do a quick check I would much appreciate it.

Thanks

Chris

[pmmunro]

Chris,

The circuit diagram of the Model 8 Mark 7 in attached.

What are you using to measure the current at the terminals? The resistance of the measuring device will have an effect on what you measure.

If you have several Avometers, a Model 40, for example, would give you a lower resistance on its current ranges than a Model 8.

A digital multimeter will have around 1 ohm across the terminals on the 300mA range.

PMM

[Chris_A]

PMM,

I had used used a Fluke 87v, admittedly I know it will have an effect but hadn't looked to see how much.

I am just trying to get an idea of the value to justify the use of a safety ohmmeter on a 2-3 ohm circuit which is current sensitive.

Chris

[micheal]

Hi, you do not get current across the terminals only voltage, on the X1 ohms range the Avo will supply 75m/a

Mike

[micheal]

I should also have said it is 75 m/a into a short circuit and a terminal voltage of approximately 1.5 volts depending on the cell’s internal resistance

Mike

[Chris_A]

Thanks a lot guys that should give me enough to go on

Chris