Welcome to the N1IR Electronics Website. Totally off the cuff, one take, unrehearsed video projects for anyone interested in amateur radio, electronic design, makers, hardware hackers and science.

Get off your duff and build something!
Training the hand and mind since 1982.

Thursday, February 14, 2013

NE555 Timers From China

Just orders 100 NE555 Timer off ebay for $9.98 with shipping . Got it within 10 working days via 1st class China Post. Each chip cost around $0.09 each. This chip was marked with the Texas Instrument logo NE555, HYC 252G. I have no idea if they are genuine they are probably grey market re-badged.

Our normal distributor each chip is $0.24 per 100 with shipping not included. Also a lead time of 2 months with our PO system (snail mail) and shipping (UPS ground). Overall we order about (5000) NE555 per year, so if we switch over to China we would save about $700 per year, but the catch is you need an ebay account and a credit card, slim chance of that happing.
I tested all of them in a astable mutivibrator circuit with a 97% pass rate, 3% failed with voltage output issues, they did oscillate at a frequency but at a diminished voltage. A 97% pass rate is fine for what we do, all of our designs we add an IC socket so if it fails it's an easy swap. Also our circuits a novelty items (buzzers, LED flashers, etc.) and laboratories, there not in high reliable systems / life support or in safety systems.

One chip I tested was really strange. It ran about 40 times higher frequency that what the other comparison chips in the circuit. I placed the chip in the circuit a half dozen time and it came back to life, really weird.

I set up a zif socket and a few resistor and caps, 2K, 1K, and a .1 uF cap and a 1uF cap as a filter cap on the supply.

 ZIF Socket Bread Board

 Good Signal

Bad Signal The 3%