ElectricSpidey
- Joined Dec 2, 2017
- 2,758
That's what was troubling me. Thanks.@Tonyr1084 Only because you asked...
Your circuit in post #5 will invert the signal and cause the lamp to operate in reverse,
As I showed, I already suggested the capacitor in post #2. Didn't suggest the diode because I see the cap as catching any back EMF. If I'm wrong - I'll gladly accept the critique.I suggested the diode, capacitor, and relay arrangement because it is both simple and forgiving and uses only two parts that might be unfamiliar to the TS. Also, it could be asembled with crimp connections.
The diode is mandatory so that the other loads do not discharge the capacitor. The capacitor holds the charge so that the relay will stay pulled in. The diode is absolutely needed. During the pulse on time the capacitor charges, during the pulse off time the diode keeps the rest of the loads from discharging the capacitor, so that the capacitor can keep the relay activated. So the diode allows the capacitor to stretch the pulses.As I showed, I already suggested the capacitor in post #2. Didn't suggest the diode because I see the cap as catching any back EMF. If I'm wrong - I'll gladly accept the critique.
Hi Jayendra,Thank you for sharing this circuit. However as said above, the cabin light has constant positive supply and the dimmer sends PWM signals through ground when the door is opened. So it would be great if you could help me with the circuit for this setup. Thanks in advance
What's your concerned to caused you to added the Lowpass filter?Almost. Lowpass filter >> window comparator >> power transistor (or relay) >> added light.
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The new lamp is a RGB Strip and uses a dedicated controller, which requires 12v - 24v. So it is not PWM dimmable. Using the above circuit, can I add a relay after the MOSFET? Will that work?Assuming the PWM is low side and the new lamp is PWM dimmable.
View attachment 255634
The source is connected to positive.
The drain is connected to the lamp.
The gate is connected to the resistors.
A rough sketch of the circuit would be greatly appreciatedThe diode is mandatory so that the other loads do not discharge the capacitor. The capacitor holds the charge so that the relay will stay pulled in. The diode is absolutely needed. During the pulse on time the capacitor charges, during the pulse off time the diode keeps the rest of the loads from discharging the capacitor, so that the capacitor can keep the relay activated. So the diode allows the capacitor to stretch the pulses.
Thank you. Will work on this and test it out. I assume this wouldn't cause any effect on the original dome lights and the PWM controller.Here's the circuit, taking the 'ground-end dimmer' into consideration.
I don't think a relay coil will respond nicely to a PWM squarewave, especially if the PWM freq is a harmonic of the armature/spring natural frequency.What's your concerned to caused you to added the Lowpass filter?
Nope. It doesn't. Either it's me or it's the painter of the portrait. A "PICTURE" paints a thousand words. Your description only used 171 words. Lacking color and definition. The TS asked if you could draw a picture, not describe the Mona Lisa.I hope this explanation is adequate for those who are unable to visualize very well.
I do not have drawing capability on this computer. And lightning got the other computer that did have drawing programs. And what was left out of that explanation that is so hard to understand??Nope. It doesn't. Either it's me or it's the painter of the portrait. A "PICTURE" paints a thousand words. Your description only used 171 words. Lacking color and definition. The TS asked if you could draw a picture, not describe the Mona Lisa.
Why are you being so negative? Santa got you on the naughty list?
Connects to both one side ? ? ? Got me confused.The cathode of the diode, the end with the stripe, connects to both one side of the relay coil (underlined by Tonyr1084)
"both one side of the relay coil and the positive terminal of a capacitor," . This is one sentence, with the word "BOTH" implying that two items follow.Connects to both one side ? ? ? Got me confused.
NoThe new lamp is a RGB Strip and uses a dedicated controller, which requires 12v - 24v. So it is not PWM dimmable. Using the above circuit, can I add a relay after the MOSFET? Will that work?
by Duane Benson
by Aaron Carman
by Duane Benson