Newie Question--Help with Connecting Ammeter

[Mike Swanson]

Hi,

I was wondering how to properly connect the analogue ammeter to the primary battery--the group experiment document says that it should be connected in series with the negative terminal of the primary battery. Err forgive my laiety but what do I do with the negative connection to the ammeter? Tried the pos of meter to neg of bat and pos of bat to neg of meter but I get sparks . Then I tried it in parallel and same thing. Maybe my clip leads are too thin?

[John_Koorn]

Mike,

The negative of the ammeter goes to the negative terminal of the battery. The positive of the ammeter goes to the wire that is connected to the emitter of the transistor.

It's normal to get a little spark when you first connect the primary battery, but if the ammeter shows that the primary battery is drawing current after you connect it and before you spin the wheel you probably have a fault in the circuit.


John K.

[Mike Swanson]

Ah great, thanks John. Makes sense, you are connecting the meter upstream and downstream to measure the current through the little bypass? I hooked up the positive of the ammeter to the wire coming off the transistor emitter just after the solder joint and I connected the negative of the meter to the negative of the battery. I got a zero reading on the 5 amp scale. . Just in case the labels on the meter were switched I switched the leads and still zero reading. I saw the meter move downwards quite a bit when I very briefly shorted it to the battery . So I checked the resistance of the meter to see if the fuse blew out then I checked the leads and both show 0 ohms. I have a little 3W 12V bulb that I tried to check with the meter with the neg of the meter on the battery neg and the positive on the clip lead. Still reading 0. Hmmmm, faulty meter or does my wheel draw ZERO AMPS YES! Might be something I'm doing too as I've not had any experience measuring amps. Any ideas?

[John_Koorn]

Mike,

You need to use an analog panel type ammeter. You did give the wheel a spin didn't you?

John K.

[Mike Swanson]

Mike,

You need to use an analog panel type ammeter. You did give the wheel a spin didn't you?

John K.

Ahh you know what...the meter has to be part of the circuit--I was connecting the primary negative wire to battery AND to the meter. Connecting the wire coming from the emitter to the meter positive ONLY and then connecting the meter negative to the battery makes the meter part of the circuit and thus it measures the current flowing through it. My previous analogy about making a bypass is not right, you have to make that part of the stream flow through the meter only. . Duh... meter works now! Thanks for your patience, John! Now I can get experimenting!

[acedragoni]

Connecting Ammeter to measure output to the chargng battery?

Hi John, thanks for this info.

How about connecting another ammeter to measure the output to the charging battery?