It is 720μs wide, so HOW can it be 720ms wide??
What it shows on my 'scope anyway.
They are missing the 0.72ms
Max.

Max I need to replace VR1 (the 10k variable resistor) with a DC reference voltage in the range of 0 to 5v. Any ideas how I can implement this?

 

What is the source of the 0-5v signal?
Is it still manual control?
Are you using the 555 circuit, if so what is the Vcc.
Max.

 

What is the source of the 0-5v signal?
Is it still manual control?
Are you using the 555 circuit, if so what is the Vcc.
Max.

My group member has designed a user interface unit which with a keypad which produces an output voltage in the region of 0 to 5 V(reference voltage). I am using a 555 and I plan to trigger it with the H11L1M configuration from AN3006. I have an idea of what I need to do to incorporate the reference voltage mentioned above. Do you think the circuit attached will work? well just the DC part up to the 555.

 

My group member has designed a user interface unit which with a keypad which produces an output voltage in the region of 0 to 5 V(reference voltage). I am using a 555 and I plan to trigger it with the H11L1M configuration from AN3006. I have an idea of what I need to do to incorporate the reference voltage mentioned above. Do you think the circuit attached will work? well just the DC part up to the 555.

And Yes. Vcc is 5v

 

And Yes. Vcc is 5v

The op-amp there is being used as a comparator. Also my circuit will only have one of the inputs either DO_1 OR DO_2 as labelled in the attached circuit

 

Not sure of that configuration working, but it would not take much to mock the LV up for testing.
Max.

 

Not sure of that configuration working, but it would not take much to mock the LV up for testing.
Max.

Thanks a million for all the advice and stuff Max. Managed to get my circuit working and my presentation went extremely well

 

BTW, if using the circuit in AN-3006 and are using a micro in place of the 555, you do not need Q1 invertor transistor, just the 10k pull up.
Max.

Hi Max,

Just looked this up.

I intend to use a microcontroller with certain previously set values of delays to control the phase and eventually speed of my 230V,50Hz single phase induction motor.

What modifications would I need to make if I were to use above circuit but with a microcontroller?

Thanks in advance.

Regards,
Vedant

 

As long as it is a shaded pole motor, fan variety, I have done it with a PIC12F629.
I based some of it on both Fairchild AN3006 and microchip AN958 & AN954.
There are also many examples of zero cross detection out there.
Similar to this.
Max.

 

Yes, I mentioned that we are not allowed the use of micros. Thank you so much for suggesting the AN-3006 Max. Hopefully I will be able to implement the circuit correctly as this is my first electronic design project.

Who is "we" and is this a school assignment? You have mentioned "group" and "we". The forum has a section devoted to school work.

Ron

 

Who is "we" and is this a school assignment? You have mentioned "group" and "we". The forum has a section devoted to school work.

Ron

Ah come on, don't go too harsh on the lad - he's new... Can have trouble finding his way out!

Cheers!