Trigger voltages of AF 540FGZ, AF 360FGZ and AF 200FG ???

[Lowell Goudge]

check here

Measuring trigger voltage

[GerryL]

Originally Posted by glasbak

My measurements.

It would seem that even from their older flashes, voltage doesn't go above 8 volts.
Thanks glasbak!
This is interesting...

[res3567]

Originally Posted by glasbak

What do you mean ? I did these measurements some (long) time ago, if thats what you mean.

Originally Posted by Blue

I believe he wants to know how to use the multimeter to take the actual measurements from the flash.

Yea. That is what I ment. How did you do that?

[glasbak]

Originally Posted by res3567

Yea. That is what I ment. How did you do that?

Just use the right tool, a high impedance voltmeter like this one :



Then use something like a paperclip to connect to the electrical contacts in the shoe, and measure the central pin which is used for triggering after the ready light of the flash goes on.

Here a detail :



George

[GerryL]

That's a serious voltmeter!
This is probably the same circa as the Takumars! Old and reliable!
I bet you these things don't take batteries!

[Blue]

It looks similar to a HeathKit.

[glasbak]

Originally Posted by Blue

It looks similar to a HeathKit.

I don't know Heathkit, not very popular on this side of the world.
But it is a Philips from around 1950, which you could know if you looked closely.

George

[Lowell Goudge]

Originally Posted by glasbak

Just use the right tool, a high impedance voltmeter like this one :



Then use something like a paperclip to connect to the electrical contacts in the shoe, and measure the central pin which is used for triggering after the ready light of the flash goes on.

Here a detail :



George

While I admire the antique you have used, it may not be as good as you think.

See my post linked earlier.

you need a really good digital meter, in the 20 Meg Ohm input impedance range to be sure of the voltage.

Old meters like this have the input impedance change with voltage range unless they are specifically identified as "vacuum tube volt meters" (the predecessor of digital multi meters) These meters are easy to identify, as they need power to work due to the tubes,

I tested an old vivitar flash with an analog meter, and depending on range, you could measure from 7 to 150 volts, but with a digital volt meter it really was almost 200 V.

[res3567]

Thank ypu George. Old or new, I need to get me one as I am packing 2 Vivitar 285s, and 2 Vivitar 285HVs. The older ones I use with a Wein Safesync hotshoe adapter and the newer ones I use with my wireless radio slaves. I have a Vivitar DF-383 dedicated to work on camera, but I may need to use my 285HVs on camera and I would like to know the trigger voltage (of all my flashes really) .

[glasbak]

Originally Posted by Lowell Goudge

While I admire the antique you have used, it may not be as good as you think.

Originally Posted by Lowell Goudge

you need a really good digital meter, in the 20 Meg Ohm input impedance range to be sure of the voltage.

I see, and my antique is only 15Mohm input impedance, but my best digital meter is even less, with 10 Mohm, what should I use then

Ah I know, I have another (even bigger) antique, that one goes to 100Mohm.

Originally Posted by Lowell Goudge

Old meters like this have the input impedance change with voltage range unless they are specifically identified as "vacuum tube volt meters" (the predecessor of digital multi meters) These meters are easy to identify, as they need power to work due to the tubes,

As you could see on the picture, light is coming out of the meter, and that is not powered by the flash unit

Originally Posted by Lowell Goudge

I tested an old vivitar flash with an analog meter, and depending on range, you could measure from 7 to 150 volts, but with a digital volt meter it really was almost 200 V.

Let me then warn you about cheap digital multimeters, they usually have only 1Mohm input impedance.
And in old flash units, the trigger capacitor is charged with resistors in the 5 to 10 Mohm range, so these 1Mohm digital meters give a seriously wrong reading.
A high input impedance has nothing to do with analog or digital, but everything with the design of the meter.
powered analog meters (usually pro stuff) are probably better than the cheap digital meters.

George

[Blue]

Originally Posted by glasbak

I don't know Heathkit, not very popular on this side of the world.
But it is a Philips from around 1950, which you could know if you looked closely.

George

If you will look at my post, you will see the word "similar." Plus, there is no Phillips logo obvious in your picture except for the blurred one.

As far a digital multi-meters go, don't under estimate Fluke etc. There is a place for analog meters but there are also things they can't do in modern electronics.

HeathKit was a company that provide kits with all of the parts required to build various kinds of equipment including short wave radios, ham unites, O-scopes, etc and were based out of Louisville, Kentucky. I think they finally went the way of the dinosaurs in the 90s.


Edit: Here is one of many HeathKit vacuum tube models

[Lowell Goudge]

Originally Posted by glasbak

I see, and my antique is only 15Mohm input impedance, but my best digital meter is even less, with 10 Mohm, what should I use then

Ah I know, I have another (even bigger) antique, that one goes to 100Mohm.


As you could see on the picture, light is coming out of the meter, and that is not powered by the flash unit



Let me then warn you about cheap digital multimeters, they usually have only 1Mohm input impedance.
And in old flash units, the trigger capacitor is charged with resistors in the 5 to 10 Mohm range, so these 1Mohm digital meters give a seriously wrong reading.
A high input impedance has nothing to do with analog or digital, but everything with the design of the meter.
powered analog meters (usually pro stuff) are probably better than the cheap digital meters.

George

no need to take offence to me not recognising the quality of you rmeter.