# 4 Tesla (40,000 Gauss) Automatic Magnetic Pulser

Joined May 4, 2020
78
Hi
I don't understand the 120VAC supply connection. Does ground from a low voltage circuit be connected with ground/neutral of 120VAC? And one side of the power supply is 120VAC and the other is 12VDC. How is that? and again I have never saw power supply one side is 120VAC and other is 12vdc

Joined May 4, 2020
78
Hi
I don't understand the 120VAC supply connection. Does ground from a low voltage circuit be connected with ground/neutral of 120VAC? And one side of the power supply is 120VAC and the other is 12VDC. How is that? and again I have never saw power supply one side is 120VAC and other is 12vdc

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#### Papabravo

Joined Feb 24, 2006
14,409
Hi
I don't understand the 120VAC supply connection. Does ground from a low voltage circuit be connected with ground/neutral of 120VAC? And one side of the power supply is 120VAC and the other is 12VDC. How is that? and again I have never saw power supply one side is 120VAC and other is 12vdc
Only if you have a death wish. Besides converting one AC voltage to another, isolation of DC ground from the AC mains by a transformer is a good thing.

Joined May 4, 2020
78
Only if you have a death wish. Besides converting one AC voltage to another, isolation of DC ground from the AC mains by a transformer is a good thing.
That circuit does not make sense

#### Papabravo

Joined Feb 24, 2006
14,409
That circuit does not make sense
You won't get any argument from me

#### scorbin1

Joined Dec 24, 2019
37
I think the power supply symbol they are showing is not complete. I think they are only showing terminals for the input side. I believe it is implied that the output of the power supply is connected to the terminals that show +12V at the bottom and the top right area of the trigger circuit. As far as ground goes, assuming all connections are wired correctly, ground is ground. Always earth potential, so technically the low voltage circuit and the high voltage circuit could be referenced to the same ground though low voltage circuits are generally isolated using a transformer and what they call ground is actually just the side of the power supply with the lowest potential. In the US 120V supply neutral is a grounded conductor, grounded at the power pole. That being said, for safety reasons the neutral conductor is never considered an acceptable ground and it is never acceptable to use the ground as a neutral, even though it should technically work. The diagram is not incorrect but misleading as far as best practices go, and possibly from a country with different electrical standards, as I said a ground would technically work as a neutral and neutral is technically at ground potential. While you could use a ground and a hot to get 120V, grounds are intended to be a non-current carrying conductor for safety use only. If there is EVER current flowing through a ground there is a problem.

The circuit on the left is the trigger circuit, and the circuit on the right is, essentially a voltage pump. It pumps energy from the 120V supply through a rectifier and into the capacitors until it reaches somewhere shy of 1KV. When voltage reaches the desired level the trigger circuit triggers the SCR and discharges the pulse through the air core coil.

#### scorbin1

Joined Dec 24, 2019
37
Here is another variation of the same schematic. This one is inteded to operate from 220VAC though.

https://bbmpulser.org/

Joined May 4, 2020
78