need help connecting power to circuit in correct way

[JAMES IRVINE]

I am at the final stage of buidling this inverter in the link **broken link removed** but I have suddenly realised that I dont know how the power from the battery should be connected to the circuit. Do I have two different wires coming from the battery with one to feed the mosfets which draw a large current to feed the transformer and have a separate wire for the controller in this link **broken link removed** or how do I do it I havnt a clue just now?

 

[ericgibbs]

I am at the final stage of buidling this inverter in the link **broken link removed** but I have suddenly realised that I dont know how the power from the battery should be connected to the circuit. Do I have two different wires coming from the battery with one to feed the mosfets which draw a large current to feed the transformer and have a separate wire for the controller in this link **broken link removed** or how do I do it I havnt a clue just now?

hi James,
Looking at the circuit, use a heavy gauge pair of wires for the battery connection [dont forget the fuse!] ,
if you have built the pcb according to the original design, the control [osc] is connected to the +12V via a +5V regulator.

So the control ic will pick up its supply from the pcb track.

Have you made any changes to the original pcb layout.?

 

[JAMES IRVINE]

I've did it on vera board this is my diagram it doesnt differ from the pcb as far as I know. I have attached the mosfets further along the vera board with the out 1 and out 2 on the same track as the gate of each p channel mosfet. I've placed the p mosfets so that the source pin is nearest to the bottom of the diagram and I have the n channel with the source facing towards the top. I have connected together the middle drain pins onto the same track with thick wire ready to be transmitted to the transformer via thick insulated wire.
My problem now is that I have three locations on my board which require power from the battery, the source pins of both p channel mosfets and the 12 volts which is connected to the controller, I'm not sure on the technique I should be using to ensure all three locations are fed from the battery, the only means I can think of is to connect all three to the battery with seperate bits of thick wire?
I don't know of another way but I think there must be?

 

[ericgibbs]

One way would be link the two FET's with a heavy wire, then run a heavy wire from the link to the battery via the fuse.
The ic controller could be a 7/0.1 wire. connected to the battery.

At the battery, twist and solder the 7's and heavy wire together.

 

[JAMES IRVINE]

Thanks Eric but I'm not quite sure what you mean though, can I connect 3 seperate wires to each position that being the two source pins of the p channel mosfets like in the diagram **broken link removed** and connect a wire to the controller and then solder these three leads to the fuse?
I was wondering how do I connect the source of the n channel mosfets to earth in fact I'm not sure how to connect any part of the circuit to earth, I've only just followed the circuit but where does the ground in this diagram lead to? **broken link removed** if you know what I mean, what do I connect it all to?

 

[audioguru]

The circuit does not need to be connected to earth. The ground symbol on the schematic just indicates that all other grounded connections connect together without showing the ground wires all over the schematic.

 

[JAMES IRVINE]

Hello Uncle scrooge thanks for that but after I have joined all the ground wires onto the same piece of track would I then create a connection between this piece of track and the nuetral wire of the power supply?

 

[audioguru]

You must never connect part of an electronic circuit to the power line. The hot and neutral wires of the power line are for power. The ground wire is sometimes used for grounding a circuit.

The inverter is designed to be powered by a car battery, not a power supply. A car battery doesn't have a neutral wire and the inverter circuit does not need to connect to earth.

 

[Hero999]

Generally the neutral side of the inverter is either connected to ground or the car's chassis, unless an isolated supply is desired for whatever reason.

 

[JAMES IRVINE]

A car battery has two terminals so if I connect the red terminal to the circuit what do I connect the black terminal too?

 

[audioguru]

I give up.

 

[blueroomelectronics]

I give up.

Amazing. I never thought I'd see the day.

PS James, what College course are you getting the degree for? Were there no prerequisite courses required?

The correct answer for the black terminal is "the red terminal". Yes that would work well, enjoy sparky.

 

[audioguru]

Amazing. I never thought I'd see the day.

When a school kid who knows nothing about electronics is ordered to build an inverter that is designed for an unusual transfomer with Japanese parts, and asks where to stick the batteries negative teminal then instead of saying, "where the sun does'nt shine" then I give up.
The inverter circuit is lousy anyway.

 

[blueroomelectronics]

Is it me or do we become more cynical with age.

 

[audioguru]

Teachers are supposed to teach. I guess they don't teach anymore.
School kids are supposed to learn. I guess they don;t learn anymore.
I will not talk about the very basics of electronics on these chat forums. I want to chat about exciting new circuits.

 

[blueroomelectronics]

Teachers are supposed to teach. I guess they don't teach anymore.
School kids are supposed to learn. I guess they don;t learn anymore.
I will not talk about the very basics of electronics on these chat forums. I want to chat about exciting new circuits.

Well said. Now I'm off to read Movies and more movies! ShadowCulture's Mr. Cranky Rates the Movies! and his cranky movie reviews

 

[JAMES IRVINE]

it doesnt help me much when swaheli isnt my first langauge

 

[blueroomelectronics]

The quandary is why would your college expect you to build an inverter without basic electronic and electrical prerequisites? Hooking up a battery is grade school stuff not college level material.

it doesnt help me much when swaheli isnt my first langauge

Huh? I'm missing the joke.