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LED the Sun Shine: 50-W Power LED with Dimmer Circuit

Power LEDs are getting more and more powerful. Although some can be pricey, we wanted to see for ourselves what one of these modern ‘heavyweights’ can do. Let's take a look at an LED module that weighs in at a strapping 50 W.

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Extra info / Update

Maximum continuous current 1.75 A
Operating voltage 27–28 V
Light flux 2925–3735 lumen, depending on colour
Beam angle 120 degrees
Colour temperature 3300–8000 °K
LED junction temperature 135 °C

Discussion (0 comments)

Colin55 1 year ago

Just a bit awkward to screw the leads into the terminal block when the heatsink is in the way.

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Colin55 1 year ago

Why would you want a 1.3watt zener diode when the current for a 7L05 is 100mA.

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Colin55 1 year ago

Why would you want a 1.3watt zener diode when the current for a 7L05 is 100mA.

TonGiesberts 1 year ago

The 1.3 W is more resistant in general and to the inrush current at power up and possible spikes form the switching of T1. Better safe than sorry.

Colin55 1 year ago

The 1.3 W is more resistant in general and to the inrush current at power up and possible spikes for...

The 78L05 does not have a constant or low value of resistance across its input-output terminals. If you think or say there is an inrush current, the 3-terminal regulator shuts-down immediately to prevent any more than 100mA or so to pass. This is a very important electronics fact that everyone has to know and understand. There are so many "half-knowledges" on the internet that readers are getting so much incorrect information.

2 Comment(s)

Colin55 1 year ago

You are expecting far too much from a 78L05 3-terminal regulator if you think you can supply it with 34v.

TonGiesberts 1 year ago

The voltage drop across the zener diode should bring the input voltage of the regulator within its safe input range. Please feel free to point out any aspect of the circuit that can or needs to be improved. Change and augment the circuit to your own preference. But true, in general it's good practice never to use a circuit or component to its design limits.

Colin55 1 year ago

It's just the understanding you have about the need, use and operation of the zener diode that amazes me. The false concepts and expectations need to be drawn to attention. There are so many misunderstandings in this part of the circuit.