Tom W coil tester diagram

Chuck Sea/Tac

Well-known member
On the car, the condenser and coil both get power at the same time. However in Tom's diagram, it appears the coil is energized, but the condenser is grounded at the same time. Could someone explain to me what I'm missing. Thanks. I also can't get a good/full picture of the diagram that was printed in the model a news. Could someone post it? Thanks
 
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Chuck, the contacts 2 and 6 of the relay are doing the job of the points in the car, so as the relay contacts open (points open), the magnetic field built up in the coil will rapidly collapse and charge the capacitor, which then flows back through the coil. This back and forth flow of the current through the capacitor and coil is a tuned circuit and will crate the spark across the gap, until the power dissipates to the point it can no longer jump the gap.

You are correct that the capacitor is shorted by having both sides connected when the points are closed. As soon as the points open, then the capacitor goes to work.
 

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Thanks Tom. Just picked up the relay and 300mfd cap today.

I bought a lot of my electronic parts from an electronics surplus store in MPLS, but when I went there last summer, there was a big hole in the ground where the block square building used to stand. Unfortunately we've lost several good surplus stores in the past few years. :mad:
 
Ebay has the relay for $14.95 delivered - about what you would pay from Allied with the shipping.

Mine on the way.

Joe K
 
And with the relay in hand (how do they do that?) I just ordered the K10 relay socket which is available on Ebay for less than $5 delivered.

Joe K
 
That's why more and more block and mortar are disappearing.
Amazon is having a summit with the large cereal companies ect to convince them to bypass Costco wallmart ect and let amazon ship direct to the consumer. It's a different world today, I'll tell ya.
 
That's why more and more block and mortar are disappearing.

Like Radio Shack, where I USED to buy these things and could have had them in my hand TODAY?

Unfortunately Radio Shack has gotten a little too enthusiastic in their pricing. Overestimated the "instant gratification" effect perhaps? It is true someone has to pay the lights and the heat and the minimum wage no-nothing cash register attendant whose closest familiarity with electronics is his smart phone.

Recently bought large disk (hearing aid type) batteries for wife's LED candles. CR2450 is the number and they're a common battery formerly found at RadioShack for $6.99 a copy. Now marked CLEARANCE for $4.19 for "Renata" brand.

Online bought at Amazon a Panasonic package of 10 for $10.99 DELIVERED.

Radio Shack did it to themselves.

Joe K
 
That's why more and more block and mortar are disappearing.
Amazon is having a summit with the large cereal companies ect to convince them to bypass Costco wallmart ect and let amazon ship direct to the consumer. It's a different world today, I'll tell ya.

Chuck,

Amazon put a lot of bookstores out of business that way. Now, they are putting up brick and mortar bookstores! I saw one at UTC (University Town Center) in San Diego a couple of weeks ago. I refuse to go into an Amazon Bookstore. They will probably start selling cereal there too!

Barnes and Noble is one of the last bookstores along with small neighborhood stores. I'll shop there until they are gone.

David Serrano
 
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