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  1. crutschow

    Switching direction of a 12V motor with two push-to-make switches

    Below is a circuit using two SPDT relays controlled by two switches that should do what you want: The diodes are to protect the contacts from inductive arcing.
  2. crutschow

    I smacked my finger with a big hammer

    It certainly smarts when you hit the wrong nail with a hammer.
  3. crutschow

    Want a particular switch to cutoff my auto ac from my stick shift.

    You could use a vacuum switch to turn off the AC when the manifold vacuum drops, indicating you are accelerating.
  4. crutschow

    Help with Transformer Theory

    And the ideal transformer input current would then go up to 4A since power in equals power out (ideally).
  5. crutschow

    Hello, I want to reduce 12 volts to 7 volts, how many ohms do I need using a resistor?

    You seem to have a minimal understanding of circuits, and don't answer our questions, so how can we answer yours?
  6. crutschow

    Need simple overvoltage protection - can I use a 7805?

    So are you going with that? If you used a series regulator, such as the 7805, you must deal with the minimum voltage drop of the regulator which is about 2V, so that would not work with a 5V input. You would need an LDO type regulator, some of which have a voltage drop of no more than a couple...
  7. crutschow

    Output comparison of Analog vs Digital mems accelerometer

    Then I see no obvious reason for the difference in the two readings.
  8. crutschow

    Output comparison of Analog vs Digital mems accelerometer

    Well, it seemed like the issue was resolved since you wanted to delete your post. So what is the frequency response specification for the two accelerometers, and what is the digital sampling rate?
  9. crutschow

    My relay is too hot

    Auto relays are generally heavy-duty and efficiency is not a particular concern, so they take enough coil current to make them warm. If you are concerned about efficiency, then use a more sensitive, small relay, or possibly a MOSFET to switch the power to the Gizmo.
  10. crutschow

    Output comparison of Analog vs Digital mems accelerometer

    So you resolved your issue?
  11. crutschow

    Help To Determine Resistor To Dim Incandescent Light Bulbs

    It's difficult to know how much you need to reduce the bulb voltage to get the desired brightness. A PWM circuit with a trimpot adjustable duty-cycle, such as bertus suggested, would allow you to easily adjust them to the desired intensity.
  12. crutschow

    Can I put a 3 watt speaker to a 5 watt board

    It should be okay as long as you don't set the speaker volume much above where it starts to generate audible distortion.
  13. crutschow

    Do I need a constant current or voltage power supply to drive 12V Halogen lights?

    If the bulbs are filament type halogen lamps, the a constant voltage supply will work fine with the lamps in parallel.
  14. crutschow

    VOIP setup for paging system to a warehouse horn

    You've just experienced acoustic feedback. It's a common problem with mics used with public sound systems, such as at musical concerts. There are sound amps with circuitry designed to automatically cancel such feedback.
  15. crutschow

    predator 9500 inverter voltage output measurement

    No such luck. He seems to have increased his dosage.
  16. crutschow

    Mosfets as voltage dividers.

    Rebuilding it why? Can't tell about adding variable voltage (power) and current control unless we see the schematic of the supply.
  17. crutschow

    Can I remove DC motor driver's speed control potentiometer and drive it with microcontroller DAC output ?

    You need a voltage to PWM board such as this, to drive a PWM to Motor driver, such as the D4184 posted by BJ.
  18. crutschow

    pls help need to pass for my finals

    So what are you going to have the servo do?
  19. crutschow

    pls help need to pass for my finals

    First decide what you want the servo to do, and then you can determine what the required rest of the circuit should be.
  20. crutschow

    MOSFET circuit for latch to enable switching 12 V battery power by micro-controller.

    I suggest switching the 12V, as that would eliminate any quiescent power taken by the converter supply with no output load. Below is the LTspice sim of a high-side P-MOSFET / BJT latching switch that should do what you want: It requires a positive going (0V to 3V) pulse to turn on, and a...
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