Rosemary Ainslie circuit demonstration on Saturday March 12th 2011

[neptune]

Hi Rosemary . It would be nice if you can get someone to do the negative gate circuit , but don't bust a gut because it sounds like You have your share of problems right now . So take it easy . Now some random suggestions for replicators . As I said earlier , unless someone can suggest a spiral shaped element from a domestic appliance we are stuck with a home made element . Nickel chrome wire is very common in scrap domestic appliance heaters from toasters , clothes dryers  , electric fires and storage heaters etc . Make the coil large diameter compared to its length . Wind the wire on a former . A glass bottle or jar might do to start with or perhaps a pot mug with the handle broken off . Or a ceramic egg cup? You could use Nichrome wire to make your own non inductive shunt resister , just measure the resistance with your multimeter .The mosfets IRFPG50 are now available on Ebay from Hong Kong at 2 for under 10 dollars .Batteries are perhaps the major expense .In the past I have used scrap car batteries . Remember a scrap car battery is one that is no longer capable of giving 100 amps to start a car .Go to the scrapyard armed with a car headlamp bulb , and pick the batteries the give the brightest light .Remember you can always sell them back to the scrapyard and get most of your money back .Finally It would be useful to have an AM radio to listen for the oscillations around 1.5 Mhz.

[teslaalset]

As I said earlier , unless someone can suggest a spiral shaped element from a domestic appliance we are stuck with a home made element . Nickel chrome wire is very common in scrap domestic appliance heaters from toasters , clothes dryers  , electric fires and storage heaters etc .

Maybe you could use Mug Water Heaters.
Sometimes they are called Travel Immersion Water Heater.
They are for sale for around 6 - 15 US dollars
I have one at home that has a resistance of 185 Ohms and is suitable for 220V.

[Pirate88179]

Or something like this one with a lot of surface area for its length?

@Teslaalset:

Those are cool.  I didn't know that they existed.

Bill

[poynt99]

Rose,

Indulge me in a simple exercise for which the results we can hopefully agree on: Analogy Part 1.

This is not meant to relate directly with your inductive switching circuit, it is meant to demonstrate a simple concept. Albeit, the two circuits are similar in concept.

Do you agree with the equation shown to calculate the power delivered by the battery Vbat?

V(P1-P4) is the voltage across the battery, and V(P3-P4)/0.25 allows us to determine the current through the battery. Their product then equals battery power...agreed?

If you agree, then I can proceed to part 2 of this analogy.

.99

[Rosemary Ainslie]

yes - agreed

Rosemary