The 555 timer IC is an integrated circuit (chip) used in a variety of timer, pulse generation and oscillator applications. The part is still in widespread use, thanks to its ease of use, low price and good stability. As of 2003, it is estimated that 1 billion units are manufactured every year. - ...
1
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1answer
51 views
Invert a 555 Astable Output Signal
I can't believe how much trouble I've had figuring out how to do such a simple thing.
I have a variable frequency, variably duty cycle 555 configuration in astable mode. I'm using a set of pots to ...
15
votes
4answers
481 views
Do engineers still design for volume using discrete through-hole bipolar transistors?
As a hobbyist who likes plugging BJTs and discrete components into solderless breadboard for entertainment and education, I recognise that people like me are an insufficient market to make it ...
0
votes
3answers
90 views
Inexpensive programmable RGB LED driver/IC/solution?
My desire is to have a simple setup with a dial device (ideal would be a 3 click dial with 3 distinct settings but an analog dial would also be appropriate) whereby position 1 would display a color ...
2
votes
1answer
76 views
555 timer monostable time constants
When making an monostable circuit with a 555 timber, the time that pin 3 is on is calculated using this:
time on = 1.1 x R1 x C1
My question is why is 1.1 included.
2
votes
1answer
60 views
555 timer astable time constants
When making an astable circuit with a 555 timber, the frequency of pin 3s pulse is calculated using this:
f = 1.44 / (R1 + 2R2) x C
My question is why is 1.44 included.
3
votes
2answers
95 views
What is the output voltage of this 555 timer high voltage circuit?
I'm trying to calculate the theoritical output voltage of the following 555 timer high voltage circuit.
It claims to output up to ...
2
votes
2answers
100 views
Need second set of eyes on 555 50% duty cycle soldered protoboard
I'm a hobbyist trying to learn the basics of the 555 timer, and am working off of the 50% duty cycle circuit from the National Semiconductor data sheet for the 555 (PDF pg. 10 Fig. 14) and have ...
8
votes
2answers
105 views
Why does my 555 stop oscillating under load?
I've got a 555-timer circuit. When I examine the output-pin on an oscilloscope, I get a nice square wave.
I want to turn an LED on and off, so I've attached an LED and resistor to the output pin ...
2
votes
2answers
174 views
Getting more amperage from a 555 output
I am working on making a drink mixer inspired by BAR2D2, I am using a gravity fed pump that is capable of running on a 9v battery. I am using a circuit with a 555 timer to control how long the pump ...
-3
votes
1answer
94 views
having problem in creating 555 oscillator in breadboard [closed]
i am quite new in electronics department and so have a very little knowledge about it...ok so i am going to set up a 555 oscillator.....i have the 555 timer chip, a solderless breadboard and resistors ...
-8
votes
0answers
50 views
help me in understanding theese [closed]
Design a circuit that switch ON/OFF a DC motor after every 20 seconds.
Design a two pole lowpass filter with cutoff frequency of (5+R) KHz [where R is the least significant bit of your roll number]. ...
3
votes
1answer
157 views
How to make a LED flash twice every second?
I know that I can make a LED flash using a 555 timer. How may I make it flash twice every second?
What I am trying to do is to make the LED flashes two times, then wait a second, and then flashes ...
2
votes
4answers
160 views
I need help designing a very simple timer
I'm designing a very simple led light timer based on the Pomodoro time management technique. For those of you unfamiliar, you work for a set amount of time, take a short break, and repeat.
My end ...
4
votes
1answer
156 views
LED driver circuit interfering with 555 timer?
Below is a circuit I put together that uses a 555 timer and an LED Driver:
But the strange thing I see is that the timer does not follow the 1.1*R*C equation. The led remains lit for much longer.
...
-3
votes
2answers
293 views
what is 555 Timer? [closed]
what is timer 555 ??
can any one give me some links which talk about this topic ?
or some references ? or texts ?
how can we use this kind of timer ? how to create it ?
any information will be ...
