With Instructables you can share what you make with the world, and tap into an ever-growing community of creative experts.
Tell us about yourself!
The Super-efficient USB Light
The "Reverse Joule Thief" Battery Charger
Using AC with LEDs (Part 3) - The BIG light
A Solar Powered Reading Light
Build a low cost, scrolling LED display for your Arduino microprocessor.
High Efficiency 9-volt LED Flashlight with Touch control
Musicator Jr - Mk 2
A wearable sound-to-light display, without a microprocessor - the Musicator Junior.
Any diode that can handle 150mA or more is suitable here. I've used the 1N4148 and they're still running after 5 years. If you can afford Schottky diodes they are even more efficient.
Are the diodes both the same kind?
Here is the image of the LED board shown in Step 5 with a bit more description. The resistors are hidden by Layer 2 but the green lines show where they connect.
Adding 'Oomph' to the Garden Solar Light
QS's Blinkie Thingie
A Triple Channel Musicator - the TriM...
Using AC with LEDs (Part 1)
Good point - if the wiring is exposed, a 4.7k 1/2w resistor across the capacitor will reduce chances of electrical shock, but since the circuit was intended to be hidden away in an enclosure, I did not include that.
hi, i build this and it works on 220ac 50hz. quite a bit of flickering, but point is it works. one comment, you might want to add a discharge resistor in parralel to the cap. els e that cap will shock you when you unplug the device
A high-power LED torch using a single AA-battery
Hello there!It's always questionable whether a battery is being charged on overcast days. In the northern latitudes, even on sunny days, it is necessary to point the solar cell in a southerly direction, angled approximately 35-degrees to get the maximum exposure to sunlight. A good rule of thumb is that typical solar cell will produce about 50mA to charge the NiCad under full sunlight. So that translates to about the same operating time, since the JT here uses about 50mA while operating. So basically, you'll need 10 hours of sunlight to run the light through the night. Less sunlight? Less time.That's the reason I developed alternate circuits, notably the 'reverse' Joule Thief and the Blinking Joule Thief. Both are attempts to wring a bit more operating time out of whatever sunlight we see each day.I'm a fan of the blinking JT circuit since it can multiply run times by a factor of over 3, meaning I get 3 days of "reserve" for each day of sunlight.Let me know if this answers your q!qs
Hi, great article. I have this exact problem. The Northern Ireland weather is almost always cloudy and overcast. How many hours will the battery drive the LED for?Is this my solution? or is there a better way for me to get my solar lights working in the garden right into the next morning but making sure the battery gets a good charge on a cloudy day? Many Thanks
Can i use any other microphone, like a very good one so the device registers sounds from far away (5m) ?
Arduino multi-mode lamp with soft touch switch
please provide the designing details
I found these last yearhttp://www.onsemi.com/PowerSolutions/parametrics.d...and have used every one in the sample kit they will send you for free. One set for 10, 20, 30, and 50mA plus a couple adjustable ones as well... Super flexible, will run off pulsating dc (no capacitor - but the LEDs get noticeably brighter with one) built in surge protection and they run about $0.52 each from Digikey in small quantitiesAWESOMEP.S. Supertex has a line of similar devices that are slightly both, more expensive and more flexible
Hey, can you explain me about calculation of filtering C in power supply or direct me any web link that has explained about calculating about it?I'm really confused in f, Vrms, Vp-p for DC!....................Although this may be because of my poor knowledge, Help me plzzz!!!
@spark light is just plain wrong when he says the actual peak only goes to half of 170V! The calculations above convert AC to Peak, not AC to Peak-to-Peak, so 120 VRMS * SQRT(2) = 169.7 V PEAK, approximately 170 V Peak for one half of a sine wave cycle. The other half cycle will have the same magnitude of 170V Peak, but in the opposite direction. Therefore, the peak-to-peak voltage is 170 * 2 = 340 V Peak-to-Peak.
I understand the resistor in series with the capacitor is to protect the capacitor, but how do you determine that it needs to be a 1/2W? Could I use other resistors in series with the LED branches to change their brightness, and if so, would they need to be the same Watt rating as the main resistor? Thanks.
Join 2 million + to receive instant DIY inspiration in your inbox.
Download our apps!
© 2016 Autodesk, Inc.