How to Build an Inverter[satire]

[Jon G.]

[satire]
How to Build an Inverter

I don't know for sure, since I've never built one. Someday I
hope to, though. I want to make one to hook up to a running car.

First I need a fast switch that swaps the teminals of the
battery from +/- to -/+ 60 times a second. The switch has to
handle 100 amps. For that I'd use two 1200watt SCRs. To tell
the SCR's when to turn on and off, I'd use a 555 timer rigged
for a 60Hz square wave. Then I'd run it through a 1:10
transformer, with the primary made of heavy wire able to handle
100 amps at 12 volts ac. The secondary would then put out 120
volts ac at 10 amps. Stick in a couple of capacitors here and
there, for the advanced signal conditioning model.

So there you have it. A rough 1200 watt inverter for $20 worth
of parts, that you can't buy for under $1000.00
[satire]

 

[Ken Taylor]

[satire]
How to Build an Inverter

I don't know for sure, since I've never built one. Someday I hope to,
though. I want to make one to hook up to a running car.

First I need a fast switch that swaps the teminals of the battery from
+/- to -/+ 60 times a second. The switch has to handle 100 amps. For
that I'd use two 1200watt SCRs. To tell the SCR's when to turn on and
off, I'd use a 555 timer rigged for a 60Hz square wave. Then I'd run it
through a 1:10 transformer, with the primary made of heavy wire able to
handle 100 amps at 12 volts ac. The secondary would then put out 120
volts ac at 10 amps. Stick in a couple of capacitors here and there, for
the advanced signal conditioning model.

So there you have it. A rough 1200 watt inverter for $20 worth of parts,
that you can't buy for under $1000.00
[satire]

you some options.,
don't use SCR's because how are you going to switch them off? further
more, you may not even be able to keep them on with a narrow pulse if you
don't have a minimum non inductive load and when you do that, it will stay
latched on.
you could use GTO's, those will let you switch off and on but still need
that non inductive load with narrow pulse triggers.
i suppose you could you a square wave at 60 Hz to directly control the
gate.
but in either case, you would need a negative pulse to turn off the
GTO..

i think the best route would be using some power Fets in a push pull
or H-bridge format from a square wave inverter driver.

regulation will be poor how ever. you really want to keep the
FETs saturated to keep heat down in them.

the best thing to do is make your self a sine wave inverter using PWM
into a high freq xformer.
P.S.
PWM = Pulse width Modulation

normally a sine wave reference is used with an amp to regulate voltage
that drives a PW timer which in turn may operate a flip flop
type circuit to select the pairs of trannies to drive.

its just a thought..

Jamie, you missed the word 'satire' in the subject. Mind you, Jon's post
misses the mark because he actually uses more detail of how the project is
to be done than your average clueless newbie/innocent beginner (delete as
necessary). Normally it's more like 'switching it somehow' and 'a cheap
transformer', etc.

Cheers.

 

[Jamie]

[satire]
How to Build an Inverter

I don't know for sure, since I've never built one. Someday I hope to,
though. I want to make one to hook up to a running car.

First I need a fast switch that swaps the teminals of the battery from
+/- to -/+ 60 times a second. The switch has to handle 100 amps. For
that I'd use two 1200watt SCRs. To tell the SCR's when to turn on and
off, I'd use a 555 timer rigged for a 60Hz square wave. Then I'd run it
through a 1:10 transformer, with the primary made of heavy wire able to
handle 100 amps at 12 volts ac. The secondary would then put out 120
volts ac at 10 amps. Stick in a couple of capacitors here and there,
for the advanced signal conditioning model.

So there you have it. A rough 1200 watt inverter for $20 worth of
parts, that you can't buy for under $1000.00
[satire]

you some options.,
don't use SCR's because how are you going to switch them off? further
more, you may not even be able to keep them on with a narrow pulse if
you don't have a minimum non inductive load and when you do that, it
will stay latched on.
you could use GTO's, those will let you switch off and on but still
need that non inductive load with narrow pulse triggers.
i suppose you could you a square wave at 60 Hz to directly control the
gate.
but in either case, you would need a negative pulse to turn off the
GTO..

i think the best route would be using some power Fets in a push pull
or H-bridge format from a square wave inverter driver.

regulation will be poor how ever. you really want to keep the
FETs saturated to keep heat down in them.

the best thing to do is make your self a sine wave inverter using PWM
into a high freq xformer.
P.S.
PWM = Pulse width Modulation

normally a sine wave reference is used with an amp to regulate
voltage that drives a PW timer which in turn may operate a flip flop
type circuit to select the pairs of trannies to drive.

its just a thought..

 

[Fred Abse]

To tell
the SCR's when to turn on and off, I'd use a 555 timer rigged
for a 60Hz square wave.

On is easy, off not quite so easy. Reminds me of the story about the guy
in the lab asking the guy at the next bench "What sort of turnoff time are
you getting with that SCR?". Back came the answer "I've been trying to get
it off since half past eight this morning"

 

[Jon G.]

Thank you, Jamie. You know more than I do. I found a web site
with schematics for various inverters. I don't understand how
they work, but it may (or may not) be cheaper to buy the parts
and build one, than to buy one outright.

http://www.theverylastpageoftheinternet.com/forsale/plans/inverter/inverter.htm

Jon

[satire]
How to Build an Inverter

I don't know for sure, since I've never built one. Someday I hope to,
though. I want to make one to hook up to a running car.

First I need a fast switch that swaps the teminals of the battery from
+/- to -/+ 60 times a second. The switch has to handle 100 amps. For
that I'd use two 1200watt SCRs. To tell the SCR's when to turn on and
off, I'd use a 555 timer rigged for a 60Hz square wave. Then I'd run
it through a 1:10 transformer, with the primary made of heavy wire
able to handle 100 amps at 12 volts ac. The secondary would then put
out 120 volts ac at 10 amps. Stick in a couple of capacitors here and
there, for the advanced signal conditioning model.

So there you have it. A rough 1200 watt inverter for $20 worth of
parts, that you can't buy for under $1000.00
[satire]

you some options.,
don't use SCR's because how are you going to switch them off? further
more, you may not even be able to keep them on with a narrow pulse if
you don't have a minimum non inductive load and when you do that, it
will stay latched on.
you could use GTO's, those will let you switch off and on but still
need that non inductive load with narrow pulse triggers.
i suppose you could you a square wave at 60 Hz to directly control the
gate.
but in either case, you would need a negative pulse to turn off the
GTO..

i think the best route would be using some power Fets in a push pull
or H-bridge format from a square wave inverter driver.

regulation will be poor how ever. you really want to keep the
FETs saturated to keep heat down in them.

the best thing to do is make your self a sine wave inverter using PWM
into a high freq xformer.
P.S.
PWM = Pulse width Modulation

normally a sine wave reference is used with an amp to regulate
voltage that drives a PW timer which in turn may operate a flip flop
type circuit to select the pairs of trannies to drive.

its just a thought..