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draco_americanus

Member Since: May 4, 2009

Country: United States

  • I just built the example shown but i took it to 4 displays like in the one picture, i stayed with the 2.2k resistor for the led current and it’s more then bright enough for the full display, the one main difference i noticed with the lm3916 over the more common lm3914 is with the way it drives the leds, the 3914 will only drive the load (led,lamp) when it has enough level to fully light the led, this device will drive the leds at an analog level, the next led (when set as a bar graph and not a dot mode) will be dimmer and up the brightness as the signal level goes up and makes for a great VU display unlike most VU displays i have come across, so it’s a more pleasing display. the example shown here only uses 2 displays but it is easily expanded. These are a great way to get a easily unique display for a budget price. It also responds to the input a lot faster then i had expected, great weekend project, i do recommend using a breadboard to work out the bugs before committing to a soldering project, i will be making them as a stack using two radio shack #276-170 boards to build this into a final project, one board for the leds and the second for the drivers mounted to the back with pin headers. the circuit is simple enough to use your imagination for any kind of layout, i went with 40 leds so i can see the display at a distance, i primarily use it at night when i need to be more aware of how loud my system is due to people needing sleep, it’s easier then using a dedicated DB meter

  • these are even used in medical devices and because they can be daisy chained quite easy with no code, just some “for me” mid level math and your good to go, i have built a few of the 3914 to see the voltage drop in cars i have had, it can be set for 13.8 and have a variance of only a few volts so i could see the failing voltage regulator and replace that before getting a tow truck, even though it’s 80’s tech they are still awesome devices to play with and have them in smd packages so they still stay relevant in today’s toys

  • I have seen a few comments on these losing power as they heat up, this is normal for a laser with no cooling, the crystal assembly is temp sensitive and is the diobe, all i did was add a heat sink to the brass part of the head and it restored most of the stability

  • my original one is indeed defective, i think it was an instability in my power supply and spiked outside it;s rage. i will try to rip it apart with epoxy remover to atlest see the output transformer, the others i have work great and from my experience in hv i would say an output of over 10kv is easy, i want to see if the can be put in parell but would need to be dc first and phasing is unknown. anyway very impressing for the size. I have a 5ma 30kv supply and it’s arc is not as impressive. anyway time to order more for fun! if i find anything interesting on dismantling the bad one i will let you know

  • OK simple and maby i got a defective one, but correct me if i am wrong but positive is red and negative is white, some how mine failed, draws 6 amps and no output and it’s only a few weeks old. maby some one messed with my lab supply or not but i ordered 2 more for kicks and giggles but this time i will have a diode reversed biased on the input to protect the device. also the output seems to be ac, i have a high voltage probe and will try to calculate the voltage later is another does not beat me to it

  • i would not recommend charging these in parallel or in series unless you have the correct balancing charger for them, they do have them listed here

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