Stuck on Experiment 11: Make Electronics

Question

I am working on experiment 11 and am stuck with a non-functioning project. I substituted 0.1uF caps for the 3.3uF listed in the book as 0.1uF were the largest ceramic caps I have..maybe it won’t do anything I can see with 0.1uF’s? Can I use polarized 3.3uF caps in this experiment? In any case the LED does not light up with the 0.1uF's.

I checked the voltages at various points and get 9V wherever there are connections to the ground rail. I also tested all of the transistors and LED in the previous experiment 10 which works. I have rebuilt this one twice with same result and can’t see my mistake.

I am hoping someone can spot what is wired incorrectly in my circuit, photos follow including schematic from book in this album:

https://photos.app.goo.gl/FaNcrS1WVVWmyyAYA

Regards

Robert Opalko

beacon_dave · Accepted Answer

Looks like you may have swapped the 470kΩ resistors with 470Ω resistors ?

Andrew J · Answer

If it helps Robert, I followed that book and made similar mistakes with exactly the same reaction as yourself . Very easy to do but I can confirm that the experiments do work and are correct. There are a couple of mistakes in book 2 but they are pretty obvious. You may also find that some parts are nigh-on impossible to come by without spending ridiculous amounts of money but there are workarounds you and work out.

jc2048 · Answer

Can I use polarized 3.3uF caps in this experiment? Positive to collector, negative to the base of the opposing transistor. Transistors: The Astable Multivibrator (Featuring SuperLEDman).

Stuck on Experiment 11: Make Electronics

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