WARNING: If do not know much about electronics then find a different topic to post in, this is for people that understand electronics well
as soon as i get some desoldering braid i will be harvesting a flyback for ignition, but i do not have the exact resistors that the wiki suggests
the wiki and other sources suggest about a 5w 220 ohm for R1 and about a 1w 27 ohm for R2
the resistors i have are:
2 10w 10 ohm resistors
1 5w
1 7W
various 1w resistors in the TV that as soon as i can figure out what they are ill post
so i would like some suggestions on which resistors i should use for R1.
Flyback circut resistor question
first:
Are the 5w and 7w resistors also 10 ohms?
and what values for the 1w resistors do you have?
If none of the 1w resistors you have will work, then you can combine them till they equal 27 ohms or around there (a couple ohms off shouldn;t matter). Basically since all your resistors are 1w or greater, you can just combine them (connect them in series) and add their values so that the total value equals roughly 27 ohms.
Are the 5w and 7w resistors also 10 ohms?
and what values for the 1w resistors do you have?
If none of the 1w resistors you have will work, then you can combine them till they equal 27 ohms or around there (a couple ohms off shouldn;t matter). Basically since all your resistors are 1w or greater, you can just combine them (connect them in series) and add their values so that the total value equals roughly 27 ohms.
Stanford Class of 2012
"In the end our society will be defined not only by what we create, but what we refuse to destroy"- John Sawhill
"In the end our society will be defined not only by what we create, but what we refuse to destroy"- John Sawhill
I can't really help until you give a little more information on what resistors you do have. Still, if you don't have the exact value you can just add resisotrs to get the right value.
What are you planning for the 1w resisotor?
What are you planning for the 1w resisotor?
Stanford Class of 2012
"In the end our society will be defined not only by what we create, but what we refuse to destroy"- John Sawhill
"In the end our society will be defined not only by what we create, but what we refuse to destroy"- John Sawhill
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jimmy101
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Like kiljoy said, add (series) the resistors to increase the value.
Rtotal=R1+R2
Or, parrallel the resistors to decrease the value. For two resistors in parallel;
Rtotal=(R1R2)/(R1+R2)
So a 50 ohm and a 100 ohm in parallel gives (50)(100)/(50+100) = 33 ohm
I would suspect that the flyback circuit isn't all that picky about the resistor values. You can proably get away with larger value resistors if that is all you have. Smaller resistors may overload the transistor and fry it.
You can use lower power rated resistors if the circuit won't be operated for more than a second or so at a time. In a TV, the flyback circuit operates continously, hence the fairly large wattage rating on the resistors to handle the large amount of heat they generate.
As a rough estimate, if you are only operating the circuit 1 second in every ten then you can use a resistor with 1/10 the wattage rating. At 1 second every couple minutes you might be able to use 1/4 watt resistors instead of 10 watt ones.
Rtotal=R1+R2
Or, parrallel the resistors to decrease the value. For two resistors in parallel;
Rtotal=(R1R2)/(R1+R2)
So a 50 ohm and a 100 ohm in parallel gives (50)(100)/(50+100) = 33 ohm
I would suspect that the flyback circuit isn't all that picky about the resistor values. You can proably get away with larger value resistors if that is all you have. Smaller resistors may overload the transistor and fry it.
You can use lower power rated resistors if the circuit won't be operated for more than a second or so at a time. In a TV, the flyback circuit operates continously, hence the fairly large wattage rating on the resistors to handle the large amount of heat they generate.
As a rough estimate, if you are only operating the circuit 1 second in every ten then you can use a resistor with 1/10 the wattage rating. At 1 second every couple minutes you might be able to use 1/4 watt resistors instead of 10 watt ones.
ok, the best i could do was a 27 ohm 1W resistor which is close to the right value, and 2.7K ohm 7W resistor which is like 10 times what it was supposed to be but oh well.
So, right now i have everything jumpered up on my desk trying to find the right coil polarity by trial and error as the wiki article suggests and i have gone through all the possibilities twice and i never got it to whine as it says it will so im looking to you guys again
So, right now i have everything jumpered up on my desk trying to find the right coil polarity by trial and error as the wiki article suggests and i have gone through all the possibilities twice and i never got it to whine as it says it will so im looking to you guys again
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- jimmy should recognize that bag of resistors in the upper left corner :P