Recent content by meereck

you are right, but the leds are high-power (current 0.4A) so the resistor would get hot pretty much. What I tried to do is the following scheme. But T3 is getting very hot when the current 0.4A flows through it. T1 is ok - they both are connected in the same manner (at least i think). Does...

Thank you for the reply. unfortunalely, that's can't be done since RGB LEDs are "common anode". If I did what you suggest, green and red LEDs would light at the same time. Dont forget that left and right diodes are in one package (denoted as slashed rectangle on the drawing), having common...

here is the schema, sorry for making it by hand. hopefully it is understandable. All I want is to switch between all green and all red.

Hello, I have a high power RGB LED with common anode. I want to have 3 of them in series, and put them on 15V power supply. And I want to switch green color on, and red color as well (something like a normal traffic light) Here is the problem: Given that three LEDs are in series, and are...

f95toli : thnx brewnog : that is the cheapest solution. Pretty cool!:)

hello, thanks for the links. It measures acceleration not speed, right. So If I move it at a constant speed, it will not work? Am I right? Furthermore, I reckon it is quite expensive, isn't it? cheers

Hello, I would like sense motion (speed) only in one direction. I don't need it to be accurate, I just want it to be a cheap solution (homemade). I googled something about piezoelectric sensing with the help of a normal crystal (or piezo buzzer?). Does anyone have more details on that? Can...

thanks guys for ideas, the frequency will be 50kHz-100kHz. I read something about using 1:1:1 transformer for differential signals. Does it make any difference? Should some decoupling capacitors be used? have a nice weekend. M.

hello, differentially, it is basically a sine wave in the range between 50-100kHz Amplitude about 0.5 Volts. I use AD620 for amplifying the signal. thanks, M.

Hello, I have a differential signal going into an instrumentation amplifier (AD620). I would like to employ galvanic isolation on the inputs of AD620. Would anyone be so kind and tell me how it shall be wired? I don't know much about signal isolation. Shall 1:1 or 1:1:1 transformer be used...

thanks for a reply. The inductance will be about 100-300 microH, its pure resistance will be 30-200Ohm. >>measuring the in-phase and quadrature components of the divided AC voltage waveform. Right, but this will probably be quite difficult to measure by a common microcontroller such as a PIC...

Hello, I need to measure ONLY a change in inductance of a loop (long wire) which has got resistance about 30-200 ohms. I have tried to build the oscillator according to this schematic : http://ironbark.bendigo.latrobe.edu.au/~rice/lc/ but the problem is it works well with an inductance with...

I suggest you to take a look at the following application notes: Analog Devices AN 709 (right now can be found here http://www.analog.com/UploadedFiles/Application_Notes/2001119207465975025AN709_0.pdf ) Microchip AN685 -...