Can't get an 555 at the right frequency

[Niels Popping]

I'm trying to build an frequency regulator. it has an 230V input voltage at 50HZ, that needs to be converted up to 1KHZ.
First I make an DC 230V with some rectifiers. than an 555 circuit on an external 9v adapter is used to create pulses that switches an SSR.
with some resistors that can be selected , I can create pulses between 50HZ up to 1KHZ. the output will be pulsed.

In simulation this works perfectly. but in practice the 555 has an output above the kHz range when the resistors is set up just for 50HZ.
I used this circuit http://www.ohmslawcalculator.com/555_astable.php
with R1 as 1K , (tried different values )
R2 is between 14K and 300K. C1 47NF.
when I put an speaker at the output an high tone noise is produced , not the low frequency I want to switch the SSR.

I don't know what to do anymore, I just need an controlled frequency

 

[ericgibbs]

hi Niels
The 47nF is far too low a value for 50Hz to 1KHz
You need a 0.47uF
Look here.

E

 

[Niels Popping]

hi Niels
The 47nF is far too low a value for 50Hz to 1KHz
You need a 0.47uF
Look here.

E

thankzz I will try

 

[audioguru]

It is too bad that you found a 555 calculator designed by a kid who is only 10 years old and knows NOTHING about electronics and simple arithmetic.
With 10k resistors the datasheet of the 555 from a respected semiconductor manufacturer shows about 560nF which is 0.56uF, not 47uF and not 47nF.

 

[Niels Popping]

I get an true pulse now of 100hz , so it works I replaced the 47NF with an 680NF

 

[ericgibbs]

It is too bad that you found a 555 calculator designed by a kid who is only 10 years old and knows NOTHING about electronics and simple arithmetic.
With 10k resistors the datasheet of the 555 from a respected semiconductor manufacturer shows about 560nF which is 0.56uF, not 47uF and not 47nF.

The '10 year old kids' calculator works OK, its the OP who entered the incorrect capacitor value.

 

[audioguru]

Wrong kid.

 

[4pyros]

It is too bad that you found a 555 calculator designed by a kid who is only 10 years old and knows NOTHING about electronics and simple arithmetic.
With 10k resistors the datasheet of the 555 from a respected semiconductor manufacturer shows about 560nF which is 0.56uF, not 47uF and not 47nF.

How do you know it was done by a kid?

 

[audioguru]

Quote: "How do you know it was done by a kid?" (The Quote button here has disappeared)
Most Instructables were made by kids. Did you see the one where a TIP31 transistor with no resistors drives an LED? The author admitted that he was only 10 years old.

 

[4pyros]

Quote: "How do you know it was done by a kid?" (The Quote button here has disappeared)
Most Instructables were made by kids. Did you see the one where a TIP31 transistor with no resistors drives an LED? The author admitted that he was only 10 years old.

Well yes a saw that Instructable, but we are talking about a web site, witch doesn't seem to have the author's name.

 

[ericgibbs]

Quote: "How do you know it was done by a kid?" (The Quote button here has disappeared)
Most Instructables were made by kids. Did you see the one where a TIP31 transistor with no resistors drives an LED? The author admitted that he was only 10 years old.

Well yes a saw that Instructable, but we are talking about a web site, witch doesn't seem to have the author's name.

hi 4p,
I agree with your comments.
Its unfortunate that some members constantly feel the need to 'rubbish' other peoples work, without taking the trouble to read posts.

The 555 calculator on that web site works perfectly well, whether it was created by a 10 year old kid or not.
E.

 

[audioguru]

I tried the 555 calculator again and it is pretty darn accurate. Maybe when I first tried it I did or it did something wrong.
I don't think I ever used a 555 oscillator. My oscillators were all transistorized or Cmos.

 

[4pyros]

I tried the 555 calculator again and it is pretty darn accurate. Maybe when I first tried it I did or it did something wrong.
I don't think I ever used a 555 oscillator. My oscillators were all transistorized or Cmos.

Thanks for having another look at the calculator, now can you tell how old the author of the page is?

 

[audioguru]

The page does not have an author. It might be a copy from somebody else.

 

[Mike odom]

We did a remoter IR heart rate monitor for horses on our Horse Treadmill... I designed the 555 circuit that produced the carrier that the heart rate modulated. I was dutifully working out the resistor value, and my boss said, "don't put so much into it, it'll have to be changed anyway (ie, you won't get it right until testing)"... so I put extra effort into picking the correct value. But one thing I almost overlooked, the RC time constant is for 1/2 of the period (charge time, discharge time). So I had to correct to make sure I got the correct 'frequency', not half period. It didn't have to be changed!!!!