STEVE

Any one have any experience with PICs? I want to test 16 diodes at once.

I am looking to build the PIC diode tester described on the site. I would like to expand the project to test more than one diode at once. Looking at the schematic it looks like it uses 4 outputs and 1 input from the 16F84. Looking at the datasheet for this PIC, I could expand it to test 2 diodes at once as the PIC16F84 has 8 outputs and 5 inputs. Although I would like to test more than two diodes at once, are there any PICs out there that have more outputs and inputs? I could just use a bunch of PICs but I think it would be a neater solution if I could just use one or two PICs. Thanks in advance.

This may already have been answered on previous pages ... but don't have time to read all 19 at the minute! In the power supply which supplies the +/- 5 V (schematic attached) what are the two 1 K resistors for? Thanks

http://www.osioptoelectronics.com/products/02-07_PDiodeChar_OSIOpto_0.pdf "To form an ohmic contact another impurity diffusion into the backside of the wafer is necessary. The impurity is an N-type for P-type active area and P-type for an N-type active area."

Found the answer ... It's an ohmic contact to reduce the resistance between the semi-conductor and the metal contact.

On a photodiode does anyone know what the N+ region between the cathode and the N substrate is for? Thanks in advance!

Would anyone know how to go about designing a circuit to decode the MSF signal from Rugby (UK) to create a radio controlled clock? I would like to create a project displaying date and time using the signal transmitted from Rugby. Thanks in advance

You could also introduce a small circuit which indicates when the IR beam passes over the photodetector. Circuit consisting of an Op Amp and an LED (visible one!) for the output. Attach the input of the Op Amp across the photodetector, turn the IR diodes on, try directing the IR diode towards the photodetector. The visible LED will light when IR beam hits photodetector. Probably a bit more complicated than just using your camera but still another way of doing it!

I thought I would post this .pdf as I think it's quite good and explains op amps really well. It explains them right from the beginning through to complicated stuff like active filters etc... Let me know what you think! [attachment deleted by admin]

Hi Stephen, I know that the idea you have already exsists.

Just thought I'd share this with everyone coz I thought it was pretty amazing! A tiny ScanDisk memory card (256 MB) for my mobile, will miniaturisation ever find a limit?

I have just been browsing on RS and found that they have information on the changes to Pb-free solder: http://rswww.com/cgi-bin/bv/browse/Campaign.jsp?BV_SessionID=@@@@0546173223.1110150793@@@@&BV_EngineID=ccciaddedddhimfcfngcfkmdgkldfim.0&cacheID=ukie&Name=weee&logText=uk2043&logType=109 Steve

I'm haven't seen the affects at first hand of what happens when the two solders are cross-contaminated, but perhaps there won't be much chance of this happening as everyone will have to use lead-free solder and Pb solder will become obselete ???

(couldnt work out how to attach two files at once!!)

T flip flops and D flip flops are just JK flip flops with inputs connected slightly differently. I have attached schematics of each type of flip flops. Whether you can convert them depends on how close you can get to the inputs of the JK, I think this would be impossible if the flip flop you're using is on a chip, as they usually only allow one input - either D or T.