Can I post PCBs for sale on here?

#1
Due to an error by the buyer I supply, I have a surplus of handy little PCBs designed to take a 14M2 as either a 'stand alone' or mix with motherboards. It will also accept an 08M2 and give a bit of prototyping space. Its designed with download socket, the two download resistors, a wally diode and a capacitor. If not here then on ebay perhaps?

Thanks

Gareth
 

hippy

Technical Support
Staff member
#2
Via eBay or similar, or sold through your own web site, with a link to that would be the best way of doing it. That opens the least number of 'cans of worms' and would give you a greater audience.
 

rq3

Senior Member
#5
What's a 'wally diode' ?

Google didn't help much :(
A wally diode is a diode used as a current valve, kind of the classical description of a diode. Absolutely zero current when reverse biased, with infinite current and zero voltage drop when forward biased. I haven't heard the term in over 50 years. If there are wally diodes out there, I'd like to buy a few million of them.
 

premelec

Senior Member
#6
I think LTC marketed an 'ideal' diode - actually an integrated circuit MOSFET thing... pretty expensive... price per million might be ok... ;-0
 
#7
So google failed then? Well I have used the term in my teaching for 30+ years 'as only a wally' would connect a battery the wrong way round :)

As suggested its just a reverse-biased diode across the power leads. I use a 1N4001 as it can cope briefly with 3 amps, usually a lot more than school battery packs can deliver. Under 1p each too at 1,000 off. By limiting the reverse voltage to around 1 volt there is no damage to the Picaxe chip. In a school environment reverse polarity connections happen all the time, more so these days as pupils rarely/have never even replaced a battery. After loosing a whole class set of 08M's in a matter of minutes many years ago I designed around the problem. Rapid Electronics distribute my ideas https://www.rapidonline.com/catalogue/search?Query=piggyaxe High functionality and flexibility derived from the outstanding Picaxe chips. I have a surplus of the 14M2 motherboards and will list on eBay.

Ironic that in our modern age, the only board to sell in numbers is the 555 two led flasher. I first used that in schools in 1988.....

Gareth
 

lbenson

Senior Member
#10
Good idea with the reverse polarity protection diode.

You might wish to add "20 pcs" to your listing title to make it clear to someone who doesn't read the text that the auction is for 20 bare boards.
 
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