Quote:
Originally Posted by rcheshire
A neat way to do posts is to wind 3 or 4 turns around the post first.
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Good idea. That should tidy things up a little. Still, it will be a while before I will try soldering anything really delicate.
Quote:
Originally Posted by wasyoungonce
Stu..the Headroom voltage is head room for the +12V regulator only. What this means is that for the 12V regulator to actually regulate voltage then the input voltage to it must be around 2.5V (actually some times 2.2V) above the voltage it is rated to regulate out.
The voltages you are measuring at the RCA are the minimum and maximum range of PWM (avg output) the controller can attain (due to it's design)...nothing wrong here.
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Thanks for the detailed reply Brendan. I understand what is going on now. This little project has been an eye opener.
Quote:
Originally Posted by Scorpius51
The 'headroom' voltage referred to probably refers to the fact that when you are using regulators, you are required to supply it with a couple of volts over the regulated voltage. Even when using low dropout regulators, a volt or so extra is usually a good idea - the data sheet will tell you.
The measured voltage at a PWM output depends on the particular circuit. Some PWM outputs will range over a (say) 5% - 95% duty cycle - not necessarily 0% - 100%. If this is the case, then you will get a small voltage at the 'minimum' setting, and near maximum voltage at the maximum setting. In your case, with the LED at max when you have the setting near 50%, it may depend on the series resistor you are using with the LED. The average of the PWM voltage at your 50% setting may be providing sufficient current to fully illuminate the LED.
By the way - you would normally wire the PWM control so that the max output occurs when the pot is fully clockwise.
Good luck.
Cheers
John
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Cheers John. I still appreciate the time taken to educate a beginner. I do have a better understanding about what is going on now.
I can only blame Mr Squiggle for the PWM control being back to front / upside down. If you ever need any electonic soldering done, send it my way. I can safely guarantee an end product that will be unique ......... I can't leave it that way. I will have to fix it. It is going to annoy me every time I use it if I don't.
