Risking it all on a Poundland Purchase.

Very true! :-)

I wasn't suggesting it would be worthwhile buying the individual bits yourself, just offering information as to how Pound Shops can sell such _high_tech_ gadgets for _only_ one pound and _still_ make a healthy profit.

A very good reason to make good use of a one pound item and modify it to your purposes (i.e. an excellent example of why you _should_ fix something that _isn't_ broken - you're simply improving it to suit your needs).

Sometimes, while Poundland make a nice profit, the liquidators they bought the stuff from are just grateful to get *any* money back.

Or the factory in China has a container or two full of stuff they can't sell in China, as they've overestimated demand, so they get rid of it for the cost of shipping.

There was a batch of radio microphones that appeared in all the markets in France a while ago for a tenner, all from the same factory, of two different types. I've never seen them since.

The optimum way to guard against such a risk is to use a transformer to magnetically couple the pulses. The final coupe de grace fat pulse from the shorted transistor will only generate a few dozen extra millivolts worth of surge at most, followed by a rapid decay of voltage, followed a few milliseconds later by the safety fuse blowing.

I agree with that - but you're not going to get a transformer at those prices.

At one point I ordered a quantity of 34063, I only wanted one but there was a minimum order condition.

In the end I used a different chip so the ones I bought are still in the parts drawer.