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  1. audioguru2

    HV power supply

    Hi Radha, 3,000 Watts is a lot of power for an average person. Are you going to use it for industry? Think about your utility's power bill, if the step-up converter is fairly efficient, at 230V it would be drawing about 17 amps. How much ripple voltage can you tolerate in its output? With a 50Hz...
  2. audioguru2

    6V Ultra-Bright Chaser

    Hi EnigmaOne, I never heard of BlackFeather. Yeah, that was the guy with the laser pointer. I think my new LEDs are brighter! Let's see. At that speed, the Doppler frequency shift must make a green laser look kinda blue if it was coming toward you, don't you think? Then my new blue LEDs will...
  3. audioguru2

    6V Ultra-Bright Chaser

    Hi Guys, Watch out for those Cmos ICs in this project. I think I zapped one with static electricity by simply putting a finished project into a plastic bag (maybe removing it caused the damage). Since it is very cold here in winter, the air is very dry and static electricity builds-up on...
  4. audioguru2

    Volume

    Hi Mukhalled, That excellent quality preamp is a good one for your amp project. I hope your audio source has enough output for it because it doesn't have any gain (except for bass and treble boost). It also has an input limit of 1V RMS, so if your audio source has too much output, it will need...
  5. audioguru2

    Volume

    Kevin, This is a bridged amplifier that uses 2 amps per speaker to give nearly 24V p-p. If it wasn't bridged it could provide only 4W into a 4 ohm speaker at low distortion. But since it is bridged, it provides 16W at low distortion into 4 ohms, or even 22W with high distortion and a 14.4V...
  6. audioguru2

    Negative charge pump

    If the car radio is new, maybe it has an all-digital Class-D switching audio amplifier. They are so efficient that a small surface-mount package can provide 4 bridged amps without requiring a heatsink. I don't want to touch those amplifier ICs because they have 56 tiny legs and their "power-pad"...
  7. audioguru2

    Use a battery while charging it.

    Hi Wkng, You won't be using the battery while charging it. You will be using any extra power from the charger. If the charger doesn't have any extra power to supply your project and charge the battery, your project might not work properly and the battery won't get charged. If you use a powerful...
  8. audioguru2

    0-30 Vdc Stabilized Power Supply

    Hi Woody, Welcome to our forum and back to electronics. There are not many mods so the PCB in the SmartKit should be fine for the modified circuit. You would need a new rectifier bridge module to be mounted on the chassis and a new Q2 to be mounted the same or on its own or on the main heatsink...
  9. audioguru2

    Convert 0-30V 3A PSU to 5A or more

    Hi Kain, It is looking good. Go for it.
  10. audioguru2

    Electronic Games

    Hi Benn, Those kits probably just use a CD4017 10-output sequencer to drive 10 LEDs, with the unused Reset (pin 15) grounded. They can be used with only 5 LEDs if you connect the reset pin to the 6th output, then the sequence will skip outputs 6 to 10.
  11. audioguru2

    problem with a rectifier

    Hi Shekhar, One of my DMM's is also very cheap (about $7.00US) and it works perfectly. You won't know if your power supply project works properly unless you measure it with a meter that works well.
  12. audioguru2

    0-30 Vdc Stabilized Power Supply

    Hi Giova, The LED should light EVERY time the circuit is regulating the current. The output voltage of U3 goes low which turns-on Q3 and the LED and pulls-down the output voltage through D9. U3 is in a feedback loop with the output-current-measuring resistor R7 so its output voltage drops just...
  13. audioguru2

    Convert 0-30V 3A PSU to 5A or more

    Hi Kain, Your PCB looks very nice but I am sorry I didn't check it for you. I think you missed my discussion of R4. Its 4.7K value allows a current of only 1.2mA in the project's main voltage reference zener diode, D8. If you use a 1W zener diode for D8 like a 1N4734A (its part number or power...
  14. audioguru2

    TDA7000 - FM Radio

    Hi John, The TDA7000 isn't manufactured anymore but many suppliers still have some. I am sorry to tell you that it doesn't make a very good FM radio: mono, poor sensitivity and selectivity, high distortion and noise. Newer TDA70XX ICs are made in surface-mount only packages and are in very cheap...
  15. audioguru2

    problem with a rectifier

    Hi Shekhar, 50-60km is too far away to cause your DMM to give false readings. A high power transmitter less than 1km would. I have two DMM's. They both always give similar and correct readings on AC and DC. Yours must be defective.
  16. audioguru2

    transformer questions

    Yes, the transformer's current rating is RMS.
  17. audioguru2

    please help a newbie

    Hi Terrakota, Welcome to our forum. Your designs shouldn't need resistors with extreme accuracy. "Normal" resistors aren't very accurate anyway, a 5% tolerance is common so your 61 ohms example could be from 58 ohms to 64 ohms. The standard 5% resistance range includes a 62 ohms resistor which...
  18. audioguru2

    Chip Identity?

    Toshiba probably has a website. Have you looked for it?
  19. audioguru2

    Chip Identity?

    Thanks John, I should have looked at the details, they are not the same. Toshiba added an extra output transistor to their TA75393 copy of National's LM393, resulting in a guaranteed output sink current minimum of 65mA, compared to the LM393's minimum of only 6mA. Therefore the TA75393 has a...
  20. audioguru2

    Chip Identity?

    Hi Felto, There are lots of links on Google. Most of them list the TA75393 with the LM393 in their title.
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