Driving Point Impedance Polesview story

http://forum.allaboutcircuits.com – I am currently having issues solving this problem as I have not been asked to solve for something like this before. Any help would be much appreciated. Image is attached. Attached Images Bm6eG9XIIAA7DHL.jpg-large.jpeg (43.6 KB) (Embedded)

LED series with dimmer?view story

http://forum.allaboutcircuits.com – So I'm not the best at all of this stuff and I don't understand circuits and all this electronics stuff nearly as much as a lot of the people I see posting in here so I figured I'd ask for help. I am pretty good at stringing together simple series of LEDs, but that's about the extent of what I can do. (Embedded)

Increase LED rope brightness on small intervalsview story

http://forum.allaboutcircuits.com – Hi everyone! I'm new here and getting back into circuits. I'm working on an LED light organ. I attached the schematic, it's pretty simple. It hooks up to a 3.5mm audio input and flashes some LEDs when the bass in the song hits. I'm using LED strips from this website here for my lighting I've got it working just fine, with only one minor problem. (Embedded)

Simple NPN Switchview story

http://forum.allaboutcircuits.com – I'd like to use an NPN to switch a small load, either saturated or off. In the attached circuit, +VBAT varies between 3V and 4.2V and the base logic operates at 2.8V. I'm planning to use a BC817-40 (datasheet here). My calculations are: Ic = 4.2 / 10000 = 0.42mA Ib = 2.8 / 4700 = 0.50 mA I know it's not usual to have Ib>Ic, but with Hfe of approx 400, it'll be saturated! If I'm r (Embedded)

Li-ion Pcb Charger Not Workingview story

http://forum.allaboutcircuits.com – I'm trying to charge 4 x #18650 4.2V 4.5Ah Li-Ion batteries. Like these: http://r.ebay.com/zu9OjA i'm using this charger: http://r.ebay.com/6hk1Op This charger does not appear to be working. Surely my own error. When i charge some good 18650's (not full, but have at least 3V charge), i do not see any of the batteries getting charged. (Embedded)

Best component ID web-siteview story

http://forum.allaboutcircuits.com – I recognize many electronic components, but a few still elude me. Is there a cheat sheet that I can download that has: 1. Photos 2. A brief description of the components function 3. How to test each one? Thanks, Gary My current project is to try and repair two old computer power supplies that won't turn on. (Embedded)

Help Understand currentview story

http://forum.allaboutcircuits.com – In attached circuit I want to know why there is 6.5mA of current flow in 2nd leg? Shouldn't all current flow through to leg 1 (only diode attached)? Attached Images CurrentFlowLeg2.jpg (13.1 KB) (Embedded)

Synchronous Motor Help Needed!view story

http://forum.allaboutcircuits.com – I just stripped my broken microwave and got this handy dandy SM16F BY36P1A3 synchronous motor out of it. Now that I have the motor, I would very much like to use it to control a door lock. The issue is, while I can get the motor to move in either direction, the way it switches is seemingly random. Just whenever I flip my on/off switch it could either go CW or CCW. (Embedded)

Shipping from Chinaview story

http://forum.allaboutcircuits.com – Now I see how they do it. Received this confirmation that my \$1.47 order is on the way.:) "We are excited to inform you that our Mr. Pigeon has started off and covered 25% of its journey. As stated in our auction, the shipment will take about 10-25 days during the delivery. Please be patient and wait for the arrival of your lovely item." (Embedded)

More free and not so free industrial surplusview story

http://forum.allaboutcircuits.com – Free "GO" power line monitor. NIB 400vac 3phase trips @ 3-4.5% unbalance in 4-5 seconds or 10% low voltage. \$5.00 each: Furnas overloads. Trip levels vary. Passive current relay. Opens dry contact at set ac current level. Works with only one or two legs connected as I recall. (Embedded)