Archive for the ‘Electromechanical’ Category:

2019-06-12 Plug-in Coils Pros And Cons

from FB group Regenerative Radio… Jun 13 I’ve thought about using plug-in coils, but I’ve had experience with Grid dip meters and there are a few important issues that must be dealt with. One is, what happens to the unused coils when the equipment is not in use. They get separated from the equipment and

(Read More…)

2019-04-29 Center Tapped Voice Coil And OTL Circuit

from FB group Vintage Transistor Radios Apr 29 Robert Abend Yeah, thanks for bringing that up. Many of the GE radios have a center tapped coil in their armature speakers. I never really thought about the unusual CT voice coil. The most important reason why is that a voice coil moves and has to be

(Read More…)

2019-01-27 Replacing Corroded Battery Contacts

From FB group Building Transistor Radios 2018-01-27 Many of the radios I’ve acquired were so corroded that I had to replace metal parts. I used tin can lids to make replacement battery holder contacts. The steel is springy enough to hold cells in place. Scissors can cut the steel, and it can be drilled and

(Read More…)

2018-08-29 High Temperature And Nylon Screws

From FB group Hobby Electronics, 2018-09-01 I faced this dilemma before. I’ve repaired power supplies where the transistor failed because it was not held tightly to the heat sink because of a nylon screw that got hot. I used a steel screw and a fiber washer, and heat shrink tubing over the threads to insulate.

(Read More…)

2017-09-19 Giant ‘Analog Meter’ For Clock Display¬†

FB comment “Brilliant!” Preet Sangha said, and I agree, but since I have a hard time seeing small meters across the room, I thought up another, bigger meter.  How about this? Instead of meters, use a printout of a meter face, full page size.  There will be one for each hour, minute and second.  These

(Read More…)

2017-09-10 How Long Can An Arduino Circuit Last?

My answer to a FB Arduino group question on Sept 17 Dan Rogers has the right idea.  The protoboard, with all the holes in it, was never meant to be permanent.  The contacts in each hole lose their springiness as they are used to hold wires.  The contacts can become intermittent after awhile.  As time

(Read More…)

2017-06-04 Making A NC Switch Look NO

I’ve been thinking about this for awhile.  Let’s say I have a switch, for example a thermal switch that only has contacts that are NC (normally closed) until a certain temperature is reached.  At that point, it changes to open, interrupting the circuit.  But the input to my controller senses NO (normally open) switch contacts

(Read More…)

© RustyBolt.Info/wordpress
CyberChimps