The photo is of a 2N256 germanium power transistor made by Electronics Transistors. The “314” date code means that it was made during the 14th week of 1963. So this transistor turned 50 years old sometime during early April. I haven’t tried to hook it up, but it’s just cool to think that if it
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These 2N560 transistors are the only ones I’ve seen with plastic for the standard TO-5 case, which is usually metal. The size and shape is identical, even down to the little tab that sticks out. According to the Motorola Semiconductor Data Book (1969), the specifications are: 2N560 Silicon NPN Pd@25 deg. C (ambient): 500 mW
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This is a photo of the PCB inside of the battery box of the LED macro ring light. It has two AA cells, which can’t put out high enough voltage for the white LEDs, so the circuit on the PC board boosts the voltage. This draws nearly 3/4 of an amp from the two AA
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I said I’d soon be posting another one of Chris’ KD4PBJ’s projects. This is a pic of the exciter he built lighting up a small fluorescent tube. It also lights up a CFL bulb. Notice that it doesn’t use any wires, it just radiates a strong field and the light just gets excited! Another trick
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I’ve offered the hybrid transformers for quite awhile, and Chris, KD4PBJ, was the first to get some from me. He constructed a 1 kHz audio oscillator (see the photo), with a .068 uF and .0068 uF capacitor in parallel to tune the transformer to 1.004 kHz. I like the way he laid out the oscillator
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This is sort of a continuation of my Raspberry Pi blog of a few days ago. I spent a few hours last night drawing up a schematic in Kicad on the wee beasty. It wasn’t easy. I used the tutorial to get up to speed on the small stuff, like placing components and drawing wires.
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Drawn May 14, 2013. I plan on building it soon. I think it would be better to replace the 82k with a 130k and use a smaller value pot, maybe 25k. I may have to use some 1% precision resistors and capacitors to get the frequency to be stable over a temperature range and supply
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Late last week I received my order from Element 14. I got three Raspberry Pi boards and two Adafruit clear cases, with shipping and tax the total came 158 dollars U.S. and change. I already had my own keyboard, mouse, 5V AC adapter with a micro USB plug on it, a HDMI cable, and a
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I’ve been thinking about the garage door open alarm project of an earlier blog, and how to get the alarm signal from the door to wherever the alarm beep signal is going to be heard. The distance isn’t far: less than fifty feet or fifteen meters. There are some interior and exterior walls in the
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