I’m confused and a little disappointed with the kit. The whole point of it is it’s supposed to have 3 @ 5k resistors for the divider. They used 4.7k. Why... simple fix but it’s also printed on their board. Plus visually I would have place them vertically like the trigger and threshold. Maybe there’s a better version out there.

 

5.0K is not a standard E 24, E 48, or E 96 resistor value. Just for grins they could have used 4.99K.

ak

 

4.99 4.99 4.99 isn’t as good of a name

 

Contrary to myth, the 555 is not named after its internal resistor string.

https://en.wikipedia.org/wiki/555_timer_IC#Part_name

http://www.semiconductormuseum.com/Transistors/LectureHall/Camenzind/Camenzind_Page2.htm



ak

 

See all the cool things we learn here? I suppose the voltage divider values doesn't matter as long as the current is kept in check. I wonder if Art Fury made the correlation non the less.

 

The magic of the 555 is that while the absolute resistor value tolerance is relatively terrible, the ratio and temperature tracking are excellent. A line in the original product release said the device "contributes less than 1% error" to the output frequency or pulse width. This was significantly better than its only competitor at the time, the 74121. Plus it had a much wider operating voltage range. Plus it had that extra-beefy output stage. Love at first sight.

ak

 

I came to the conclusion that it made a difference if the RS Flip Flop was composed of either NAND or NOR gates.

Only in the signal polarity required to change their state.

 

I just couldn't resist.

The mighty

kv

 

Hi guys
I have problem with my abs sensor light on my 00 Jeep
Sensors cost 250 each Jeep worth about 1000
Any circuit I can use to switch light off after 3 seconds
There is a bridge in the diagnostic plug that when I take it out light goes off
Anything that I can use instead of this bridge

 

Have you tried cleaning it (the sensor)? And check the wiring for wear. For some reason sometimes it’s cheaper to change the hub bearing which comes with a new sensor.

 

Hi guys
I have problem with my abs sensor light on my 00 Jeepe

It is considered bad form to hijack someone else's thread. If you have a question about something automotive, there is a forum for that.

Also, your question is sorely lacking in detail. for those who don't speak car:

What is an abs sensor
What are the sensor output characteristics
What light
What bridge
What plug

ak

 

Only in the signal polarity required to change their state.

Thanks Crutschow,

Yes I think when I first discovered it, I wanted to trace the detailed operation of a 555 timer in order to have a better understanding of its logic.