Collector-base voltage (IE = 0). BD BD BD BD The device characteristics and parameters in this data sheet can and do vary. BD Transistor Datasheet pdf, BD Equivalent. Parameters and Characteristics. BD Bourns Darlington Transistors W NPN Silicon datasheet, inventory, & pricing.

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How are you with mosfets?

Now, putting the opto-transistor right in front of the built-in flash? And the tailing off from the phosphorous in the white LEDs bs649 become a problem at fast moving objects. I would start by re-designing this.

BD649 Datasheet

I’m working on the idea that when the built-in flash is blocked by a large macro lens at close range, the Vatasheet ring will compensate, and the camera will calculate from whatever it ‘sees’ through the lens. So I guess my main question is, how do I calculate the size of R1 and R2 so it protects both the opto-transistor and the base of the darlington at 0. Determining resistor values in datasheft mesh. Jul 22, 6.

OK thank you all for your thoughts on this. Do you realize how short that flash from the camera really is? Lets try 30 ua in ambient light.

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You suggested a 22k in series dattasheet the trim pot meter, and none in series with the opto-transistor. Nov 13, The opto-transistor can only allow. You route that to the base of the transistor. The light source consists of five series of ten bright white LEDs, each series with it’s own ohm resistor. I’d thought of this too, to protect the opto-transistor in case I dialled the trim pot meter to 0ohm.

Are you referring to R3? Suppose the PT is 5 mS and the darlington is 20 mS. I’m a newbie The recommended current through the LEDs is 20mA and the max mA OK for a short flashhence the smaller resistors when the system is in flash mode. Generally a good job for an SCR. Jul 22, 9. I’ve looked on-line and saw some hd649 without an R1 or an R2, but wouldn’t that blow the BD or the photo transistor when it saturates?

Transistor Substitute. – Datasheet/Parts requests – Community

Quote of the day. Does anyone have any suggestions? So, yes I guess the IR filter might help, but the twisted pair is perhaps excessive? As you could see from my pictures, the unit is a rectangular circuit board that slides in a Cokin filter holder with the LEDS facing forward and bd6649 opto-transistor mounted on the reverse side of the circuit board, facing the built-in flash.


I may be wrong – honestly, I’m not sure. Just playing devil’s advocate here.

Jul 21, 1. Will this work if you don’t have any way to stop the LEDs quickly? LEDs and Solar Cells Combine into Devices that Emit and Absorb Light Researchers have developed double-heterojunction b6d49 which can be biased to both send and receive light—in other words, a device that is both an LED and solar cell, capable of emitting and absorbing light.

Nov 30, 18, 9, You can not get to zero volts and you don’t need to. Whether that be from it’s own flash or any other light source. Really don’t think you are going to get that circuit to respond fast enough. Solving for two resistor values in a resistor-divider network Posted by jerseyguy in datasheeg