volts dimmer?

Discussion in 'The Projects Forum' started by ramattos1992, Apr 13, 2011.

1. ramattos1992 Thread Starter New Member

Apr 13, 2011
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0
i want to know how to make a device that uses 16vdc and be controlled by a dimmer switch from mains power, but instead of reducing the volts i want to have it turn transistors on or off at different voltage levels. would this require a micro-controller or just caps and resistors? and the output of the transistors would be a 5vdc regulated supply

2. t_n_k AAC Fanatic!

Mar 6, 2009
5,448
784
Hi ramattos1992,

Your question unfortunately doesn't make a lot of sense - to me anyway. Perhaps you could explain what you are trying to accomplish more clearly.

Keep in mind that the AAC forum is extremely wary of giving advice about any experiments involving the use of AC mains supply voltages by people lacking the necessary skill & experience in that "specialist" area.

3. wayneh Expert

Sep 9, 2010
13,636
4,431
+1 (and welcome to the forum)

I see mains, 16v, 5v, and a dimmer switch. The rest of what you need is a mystery. Some of us are pretty good at mind reading but I think you've stumped us.

4. ramattos1992 Thread Starter New Member

Apr 13, 2011
5
0
i want to have transistors connected to a 5vdc regulators, and when the mains power is adjusted the transistors will turn on or off. so
100%mains=5 transistors
75%=4
60%=3
25%=2
<25%=1

but i dont know how to control the transistors when the volts change. as simple as caps and resistors? or a micro-controller?

5. beenthere Retired Moderator

Apr 20, 2004
15,815
290
One thing you need to be aware of is that transistors and voltage regulators are DC devices. You must have a step down transformer plus rectifiers and filter capacitors to supply a reasonable level of DC for your circuit (like the 16 VDC you mention above).

However, the circuit is still a mystery. Are you tracking line voltage level? Your initial statement simply can't be understood. Can you provide a more detailed description of what you are interested in doing?

6. Bernard AAC Fanatic!

Aug 7, 2008
4,554
477
Something to start with: Mains =16V DC, which can vary from 0 to 16V & we wish to know by a 5V signal on 5 outputs when Thr V is at <25%,3.9V, 25% 4V, 60%- 9.6V, 75%- 12V, & 100%- 16V. Use 5 comparators, a V refererance, 5 resistive V dividers &, which will give a "bar graph" type output. Adding some AND gates & inverters to inhibit low order outputs, now have a single output for each of the V levels.

7. ramattos1992 Thread Starter New Member

Apr 13, 2011
5
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if i just make a bar graph using comparators that would work OK?

8. Audioguru AAC Fanatic!

Dec 20, 2007
9,462
916
Why not use an LM3914 bar graph IC that has 10 comparators, a resistor ladder, an adjustable regulated reference voltage and 10 adjustable regulated current LED drivers.
It has a pin to switch from BAR to DOT.

9. ramattos1992 Thread Starter New Member

Apr 13, 2011
5
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Do you have a schematic for the circuit?