Archive for August, 2017:

2017-08-30 The Surface Mount 1N4148 Is Very Small

I bought some surface mount 1N4148 diodes.  They are so small I couldn’t find one when I dropped it on the bench! Here’s a photo of one setting on top of a regular transistor.  It’s itty-bitty, teensy weensy!  It’s not much larger than a fly speck!  That’s it!  That tiny black rectangle sitting on top

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2017-08-29 13V Zener Diodes

I think I have enough 13 volt Zener diodes for the rest of my life.  😱

2017-08-28 Am I Seeing Things?

After paying my water bill today, I left the Orange Civic Center and I glanced over to a front yard and thought I saw a funny looking black dog.  On second glance, it was a pig!  I was wondering if I was seeing things…   😱  😛  😸

2017-08-27 A 555 Is Easier And Cheaper Than a PIC

From a FB group post. “primitive transistors” I think that’s ironic.  The 555 makes the design easier for the builder.  It has all the parts so the builder doesn’t have to build from scratch.  Like making a cake using Betty Crocker’s cake mix instead of flour, eggs, etc, and no need for a recipe.  It’s

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2017-08-20 Measuring Very Low Resistance 

From my FB comment  Some comments say measure with a meter, but fractional ohm resistors don’t measure, or barely measure with the typical ohmmeter.   Instead, you should be giving better advice.  You should use the device between your ears to find the resistance. The resistor should be put in series with another resistor of

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2017-08-19 Emitter Base Breakdown Can Damage Transistor 

From YT reply to Neilgn  2017-08-20 Take any NPN transistor and measure the gain, and write it down.  Then put a 1k resistor in series with the transistor’s emitter and connect the emitter to positive and base to negative of a power supply.  Adjust the voltage until 2 or 3 volts are across the 1k

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2017-08-16 Joule Thief Measurements Of YouTube Video

I watched this YouTube video.  I liked it, it’s a well made video.    The author asks a question about the 9 min point.  He was not sure why the voltage peaked out at about 40 volts, and then stayed the same. First, it is not wise to disconnect the LED load from the JT because

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2017-08-15 1950s Astor 7 Transistor Radio

2017-08-13 Transistor Radio Technology Timeline

My post to FB Aug 14 Does anyone know about the timelines on what I’m talking about below? The early TRs (transistor radios) were AM only because the germanium transistors available were not capable of FM frequencies.  The first TR was the Regency, and it used the Texas Instruments transistors that were similar to the

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2017-08-12 Compilers Should Be More Helpful

From  FB comment  More than 3 decades ago I took programming classes using a mainframe and minicomputer.  The error messages were numerous and cryptic, and those were for just a single mistake, such a missing right parenthesis. One would think that since then, the compilers would be more helpful, but it doesn’t seem so.  I’m

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