Proof Reading LEDs, 555s, Flashers, and Light Chasers

bertus

Joined Apr 5, 2008
20,876
Hello Bill,

Is there no need for a current limiting resistor in figure 10 of page 5 in PWM generator #1?




In the simple pwm of SgtWookie with the 4093 there is one.



Greetings,
Bertus
 

Thread Starter

Wendy

Joined Mar 24, 2008
22,170
I understood, but the current between the Hysteritic Oscillator and the PWM Oscillator is vertually identical, capacitor and all. I really do not feel it is necessary. With the Hysteritic Oscillator there was no heat at minimum setting, none what so ever, and the frequency went well into the ultrasonic with a 10µF capacitor.
 

Thread Starter

Wendy

Joined Mar 24, 2008
22,170
Hehe, I have to admit you were right about the need for a resistor, though for a slow flasher it isn't as necessary as in some schematics (because the pot will be on the high side, always). Basically when I tried a fresh battery the 555 got hot. Didn't blow out though.

But that's not the reason for this post.

Basically I'm running out of room to modify the article. I'll be able to do what I want this time, with some minor concessions, so this isn't a problem this time.

So far I've had two separate threads, the second was started because of the same problem with the first that I'm having now. I want to add chapters, and keep them contiguous. I may have to start a 3rd thread, but that isn't my prefered solution.

Blogs would work except they don't allow attachments. Thinking about it, I could still make this work, as a separate blog per chapter, with an index blog linking all of them together. Hmmm.... That could work.

Threads can be written to by other people, which means it can't be edited indefinately since I can't add more chapters in front of their comments.
 
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