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PWM LED Dimming Circuit Design Recommendations and comparison against linear dimming

I think this is the best solution for EMI on the board but this still doesn't help with the long wires of the strip. The bold part is wrong. Running high \$di/dt\$ through long wires will cause EMI ...
Rohat Kılıç's user avatar
1 vote

Does a current sense resistor not always mean a constant current output for dc-dc converter?

Does this mean that the inclusion of any current sensing does not mean a constant current output, but is just another way to output constant voltage? Having a sense resistor simply means the chip ...
bobflux's user avatar
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0 votes

Does a current sense resistor not always mean a constant current output for dc-dc converter?

I've had a understanding that having a current sense resistor feeding into sense pins or a feedback pin meant that the inductor current was changing wrt the variations across sense resistor, hence ...
MOSFET's user avatar
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2 votes
Accepted

Constant current driver issue or misunderstanding

The current regulator device needs about 2V across it to regulate properly. If I assume your LEDs drop 3V each, that's 8V total. With a 12V supply that leaves 4V for the resistor. At 30mA and 12V ...
Spehro Pefhany's user avatar
6 votes

Is an LED driver IC just a boost conv with voltage across Rsense fed into FB?

Can any boost converter IC be made to output constant current by adding in a current sense resistor? Any limitations? I'm going to answer this one first. Short answer, yes. For any regulator (closed ...
Rohat Kılıç's user avatar
10 votes

Is an LED driver IC just a boost conv with voltage across Rsense fed into FB?

No they're not just a marketing thing. The market for LED drivers for illumination, LCD backlights and such like is enormous so the chips are optimized for the purpose. Both buck and boost are made. ...
Spehro Pefhany's user avatar
0 votes

Relay to read only pulse signal not constant signal

An on-delay timer will do what you want. If the relay is energised for > preset time the relay will energise. If you get one with a changeover contact you should be able to do any required logic. ...
Transistor's user avatar
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What is the basic idea behind the so-called "improved Howland current source"?

Basic idea The "improved" solution is not Howland's doing. Rather, it is named later after him as a sign of appreciation and respect. However, it is interesting that the two circuit ...
Circuit fantasist's user avatar
1 vote

Howland circuit gain factor

The voltage across R5 is VR5 = -Vвх.R3/R1. So, the load current Iвых flowing through R5 and accordingly, through Rн, is Iвых = VR5/R5 = - Vвх.R3/R1/R5. If R1 = R2 = R3 = R4, Iвых = -Vвх/R5. Brilliant ...
Circuit fantasist's user avatar
1 vote
Accepted

Howland circuit gain factor

This circuit seems to be an "improved" Howland circuit. Here is how it should be "solved" ... Maple sheet. The current I solved is the current in R2 resistor. Note how R5 and RH ...
Antonio51's user avatar
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