DIY CIRCUITS ELECTRONICS

ultraviolet exposure device i built few months ago. it is controled by an arduino pro mini and has a 7 segment display to show the set and remaining exposure time. it uses ultraviolet leds(49 total)bought cheap from ebay. you can wire the arduino and the rest components using the diagram below.this way i made it too.you can connect any common cathode 7 segment display as long as you know witch pin is the segment shown in the diagram.or you can find it by applying about 3volts to each pin to see witch segment lits and write it down.(as i did)or downloading its diagram if exists.. then programm the arduino with the code given in the link below.you can skip the circuit with the mosfet and the optocoupler and connect a 5 volt relay as shown in the diagram(relay output & ground) to controll the leds. if you liked this project please subscribe to my channel for more future projects.... arduino code : https://drive.google.com/open?id=1SK-jNM7jZIcx-jIN8e3rleN_-12L9IQG

mini teardown of a working very old cd player by analog & digital systems inc. manufactured in january 1986.   and here are some photos...

CAMCORDER DIY LED LIGHT WITH WARM - COLD ILLUMINATION ADJUSTMENT     VIDEO ABOUT THE CONSTRUCTION     very usefull diy led light with warm - cold adjustment perfect for filming videos.it consists of cheap & easy to find components and modules.it is powered of 18650 li-ion batteries and includes charging circuit. the illumination tone can be adjusted to warm - neutral or cold by two potentiometres. it uses a boost converter circuit to keep the output voltage stable for the leds so the light produced remains stable until the batteries are fully discharged. there is also a buck - boost converter for charging purposes that is adjusted to provide a constant current - voltage to charge the batteries.it can be powered from 5-25 volt and the current required is about 2amps. here are the components used...(search with these terms) 3W High Power cool/warm white 3000k 4000k 10000k-30000k LED + 20mm star pcb   AMS1117-ADJ REGULATOR CI...

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