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  1. W

    Problems charging a lead-acid battery

    Yeah I think I've come to terms with this stopping in it's tracks at this points. Thanks to everyone and their help, I appreciate it.
  2. W

    Problems charging a lead-acid battery

    Thank you for the prompt response Dave. I had tried what tfr000 had suggested, where I set the voltage to 14.5, then shorted the outputs and set the current limit to 1.5A. However when I turned it on it did what I mentioned in my first post. It starts out drawing only about 150mA, and it will...
  3. W

    Problems charging a lead-acid battery

    Hello Dave, sorry for the late reply. I checked the battery. All that it says, aside from things like "Do not dispose of in fire", etc, is 12 VDC Sealed lead-acid battery 5 Ah. It also mentions that during charging, the amount of initial current should not exceed 1.5 A.
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    Problems charging a lead-acid battery

    I was wondering if there would be any harm in leaving it running at 3A, but when I first tried it out, after about 10 seconds, I could hear some unnerving sounds coming from the battery, so I switched it off.
  5. W

    Problems charging a lead-acid battery

    Thank you sir, I appreciate it.
  6. W

    Problems charging a lead-acid battery

    I don't have the battery or resistor in front of me, so I don't know it, but I can get back to you on that. But the resistor was several kOhms and 1 Watt. But it is a small LA battery probably used to start a motorcycle. On the battery, it lists the charging voltage as anywhere from 13.8-14.5...
  7. W

    Problems charging a lead-acid battery

    Hello guys, I have a problem charging a lead-acid battery. I have a 0-30V 0-3A power supply. If I hook up the power supply directly to the battery (with a resistor and/or diode) and set the voltage to an appropriate level, the LA battery will only draw about 150 mA. After a few minutes...
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    Warming a laser diode using a thermistor

    Well what I feel it will really boil down to is how much and how quickly the heat is generated. Assume your typical alkaline AAA battery has 1200 mAh of charge (http://en.wikipedia.org/wiki/List_of_battery_sizes#Round_batteries). And assume you choose a thermistor such that it draws 100mA...
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    Warming a laser diode using a thermistor

    I use a green laser pointer at night to do astronomy related work. I got a cheap $5 green laser pointer off of ebay, and when it's a warm summer night, the device works fine. However, the second it touches the cold, it fizzles out and gives me almost zero output. My idea was to use a...
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    Can I replace an LC circuit with a crystal?

    I checked the FCC's regulations. They outline a specific section for hobbyists making low power unlicensed transmitters. I'm perfectly within my rights to make this transmitter. And thank you for the advice about the resonator.
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    Can I replace an LC circuit with a crystal?

    Hello all, I am trying to make an FM transmitter that operates at only 1 frequency. I need the frequency tolerance to be very high, so I'd like to choose a crystal instead of an LC circuit. This is the circuit I'm building: http://cappels.org/dproj/FMdist/fmdis.htm If I were to replace...
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    Method of generating 170 VDC to drive nixie tubes

    Thank you for the safety tips and your concern. I should also mention that I won't be the one doing the work, I am simply pitching the idea. I know a professional electrical engineer who has been in the field for over 40 years. Anything I pass by him would scrutinized for safety. I may...
  13. W

    Method of generating 170 VDC to drive nixie tubes

    i have never worked with anything greater than 24 V, but I would never work with high voltages unless I wear at LEAST class 00 electrical gloves (rated up to 500 V)
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    Method of generating 170 VDC to drive nixie tubes

    In order to operate, nixie tubes need 170 VDC. I know that the mains voltage is 120 VAC-RMS. So if you account for the RMS value, 120*1.414 is nearly exactly 170 V. So would it be possible to make a full wave rectifier? I decided to simulate the circuit in spice. If I use a 500 uF capacitor...
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    Is there such a thing as an inverted zener diode?

    Zener diodes act like regular diodes, except that they allow current to flow in the reverse direction if the voltage is high enough. That is, current with voltage ABOVE a certain value will flow. My question is, is there such a diode that only allows current to flow if the voltage is BELOW...
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