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  1. K

    Use Of Current Source?

    For DC, it's nearly infinite; for AC or other changing signals, it's lower due to gate capacitance.
  2. K

    to make an LED blink

    Most pre-packaged blinking LEDs blink faster than 5 seconds on/1 second off. An ATTiny or 6-pin PIC10F part would work great, but would probably draw a bit more current than the existing solar light circuit. You'll also need a boost converter since most electronics including LEDs need a bit...
  3. K

    to make an LED blink

    Does your garden light have a photocell to sense daylight or does it use the solar panel? Maybe "leaking" some of the LED's light to the photocell or solar panel will cause it to cycle on and off. Add a capacitor to slow down the rate of flashing. Another thing I've noticed with the garden...
  4. K

    Hi, pretty basic question about a simple CMOS TTL circuit

    If it's integral it probably has 6 pins: left signal in, right signal in, hazard in, left signal out, right signal out, and ground. If you can find which pin is hazard in and either left or right signal out you can hook the LED between those two. If there's only 5 pins it could be wired such...
  5. K

    How to connect the screen of a video cable

    With that short a cable it probably doesn't matter, but if you connect the shield on one side you eliminate that possibility of a ground loop.
  6. K

    free-to-air TV project

    Most signal boosters go on the antenna end of the coax, and are usually powered through the coax through an adapter so you don't have to run a 2nd wire to the antenna. Putting the booster on the antenna side compensates for signal loss through the coax. Also, the shorter the coax the better...
  7. K

    Hi, pretty basic question about a simple CMOS TTL circuit

    Also, if you can locate the actual flasher unit for the hazards (it'll look like a relay and probably is clustered with other relays in the car--it's also what makes the "click click" sound when the flashers are on), you could wire the LED and resistor in parallel with the flasher--positive side...
  8. K

    Led project

    Do the wall warts put out DC or AC? You'll need DC for LEDs, especially the ones with built-in flashers. Also, how are you wiring them? Series may or may not work for flashing LEDs, depending on how the flasher IC handles varying voltage/current loads.
  9. K

    Hi, pretty basic question about a simple CMOS TTL circuit

    It sounds like you're getting confused about the intermittent signal. You said you want your LED to flash, but in the opposite phase of the actual indicators, right? So, indicators off, LED on, indicators on, LED off? Using the gate circuit (ignore the 1st gate in my schematic, for now assume...
  10. K

    Hi, pretty basic question about a simple CMOS TTL circuit

    Here's one I just drew up, using a 4081 and a 4069. It could be made with one NAND IC as well, but if you already have 2 AND and one inverter available in your circuit, this will do the trick. I also included a transistor to drive the LED, since the 4081 can't source much current and the LED...
  11. K

    Hi, pretty basic question about a simple CMOS TTL circuit

    LSIG and RSIG into one AND gate (with pull-down resistors as needed). Send output of that AND gate to inverter (or use NAND gate), then send the inverted output to one input of another AND gate. Feed the power signal from the hazard switch into the other input of the AND gate (with another...
  12. K

    Help with identifying capacitor

    I found a datasheet for a cap with similar markings to yours: http://elcodis.com/parts/1972335/VES-100M1CTR-0405.html It appears the 1J is a date code. 100 is the capacitance (100uF). 25S is the rated voltage (25V) and a "series code". I'm not sure what this is, but manufacturers usually...
  13. K

    Help with identifying capacitor

    Looks like the board has holes for a leaded (through-hole) capacitor as well as the surface-mount one, so you could use either kind. If you're not comfortable soldering a SMT capacitor, get a through-hole one.
  14. K

    Transmitt ASCII data

    Start bits are always 0 and stop bits are always 1. If the bit polarity were wrong your data bytes would be all wrong, not just the top bit. PICs only support 8-N-1 or 9-N-1 natively, but you can do 7-E-1 or 7-N-2 in software easily enough by manipulating the top bit before transmitting. It's...
  15. K

    LCDs Normally White vs Normally Black

    For many LCD displays if you remove the polarizing filter from the front of the display, flip it over and reinstall it, it'll change from normally white to normally black and vice versa.
  16. K

    Forum Upgrade Next Week

    Only trouble is, a security flaw in the Flash(?) based uploader they were using made it necessary for that feature to be removed, so now you have to upload files 1 at a time. I presume you're upgrading to a newer vBulletin, so are you going to 4.2 or 5?
  17. K

    Mystery Component

    Can you post a pic of it? It's probably a capacitor. 104K means 0.1uF or 100nF, K = 10% tolerance, and a 630V max voltage.
  18. K

    D-flipflop freq divider

    Maybe it's something not set up right in your simulator? I created the D flip-flop version in LTSpice and it toggles properly. Try forcing unused inputs high. Have you tried building the circuit with actual parts?
  19. K

    TLC 5940 powering 512 RGB LED's

    The datasheet is here: http://www.ti.com/lit/ds/symlink/tlc5940.pdf It says you can chain 40 or more as needed. You connect SOUT of the 1st one to SIN of the 2nd, and so forth. Connect the XLAT pins together and to a single output on your microcontroller. Then you set XLAT low and clock...
  20. K

    Transistors heating up when sinking from motor

    Cool stuff. You can make Darlingtons using a 3904 and a 2222 as well, so that you can get the higher collector current of the 2222. Put the 3904 on the input side and the 2222 on the output side.
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