Search results

Search Forums New Posts
  1. Alec_t

    Hall switch magnets.

    Looks like only 3 rivets hold the strap, and the plate they're on is held in by a circlip. It shouldn't be too difficult to get the plate out and remove the rivets and strap to enable fitting of a toothed wheel to the shaft. Then re-rivet the strap.
  2. Alec_t

    So, I built a guitar neck with LEDs in it .....

    A capacitor across the LED would help to reduce flicker, but if the LED series resistor were <1k then the cap would need to have such a high value (hundreds of uF) that there probably wouldn't be enough space to fit it, or it would obstruct playing :(.
  3. Alec_t

    Electrolytic capacitor questions (reversed polarity)

    It doesn't. It says "2 Minuspol". Perhaps that signifies pin 2 is the minus pole?
  4. Alec_t

    Can you make my 12v LED light up?

    If the AC pressure switch can switch the +ve, then here's an option which would (a) turn on the green LED for any PWM duty cycle >20% if the PWM signal is a 5V one, or >10% if the signal is a 12V one and (b) turn on the amber LED when the AC switch closes. With D4 in place, the green LED goes...
  5. Alec_t

    Battery Level Indicator

    Also, what type of battery? Depending on the chemistry, the voltage may or may not be a good indicator of the state of charge.
  6. Alec_t

    What charger to use for LI-ion batteries

    Welcome to EP! Lithium batteries are fussy and need a particular charging profile if they are to be charged safely. If charged wrongly they can catch fire or explode:eek:. Have a read of this. There are special-purpose ICs available for safely controlling the charge profile.
  7. Alec_t

    Mouse driver signals - SIMULATION

    Perhaps this will help.
  8. Alec_t

    DC-DC Isolator

    Exactly what 'inputs' are you interested in ? Just the track supply voltage; or some track-superimposed signals ?
  9. Alec_t

    Can you make my 12v LED light up?

    My suggested circuit can be easily modified (perhaps simplified) to do that. Does the AC pressure switch provide a path to the +ve supply line (i.e. high-side switching) or to ground? BTW, I have assumed your LEDs are high-side switched (as shown) rather than low-side switched. Is that the case...
  10. Alec_t

    Can you make my 12v LED light up?

    Here's a suggested basis for a circuit which will turn on one LED when the PWM speed signal is above a low threshold and will turn on a second LED as well once the signal is above a higher threshold. The trim-pots allow the thresholds to be adjusted. The circuit could be modified to have the...
  11. Alec_t

    Can you make my 12v LED light up?

    Won't you want the PWM signal to drive one LED or the other depending on the fan speed?
  12. Alec_t

    Comparator - Battery Cutoff

    If you read the datasheet for the LM258 you will see that the common mode input range is from 0V to Vcc-1.5V. If your supply voltage (Vcc) is 3.7V or less, then the voltages at the inverting and non-inverting inputs must be 3.7V-1.5V = 2.2V or less for the opamp to work correctly. You need a...
  13. Alec_t

    Designing Circuit by BC546

    Your capacitor values appear to be 1 FARAD ! Re-think those.
  14. Alec_t

    Ceramic Heating Element

    Welcome to EP! We need more information to provide meaningful help. What are the heating element specifications (resistance, wattage)? What temperature are you trying to reach? What are you heating with the element? Is the heated object/medium surrounded by thermal insulation?
  15. Alec_t

    Guitar 4x10 Cab wiring

    Eh? No: it would be a matter of re-configuring the amp output and speaker connections. If the speakers are each 16Ω then you won't be able to use all four to match the 8Ω setting.
  16. Alec_t

    Designing Circuit by BC546

    Were you paying attention in class :)? Revise what you have been taught. Start by considering which transistor configurations give reasonable gain and what their input and output impedances are likely to be. Post your best effort at a solution.
  17. Alec_t

    How to Pass Power to spinning components on a High DC Speed Motor

    Rotary transformer?
  18. Alec_t

    Garment Steamer

    112C sounds reasonable. Let us know if it does the trick.
  19. Alec_t

    Differential Pressure Sensing

    I think you'll need two sensors: one for A/B diff pressure and one for B gauge pressure.
  20. Alec_t

    EMG amplifier circuit.

    This is the parallel of a thread over at AAC.
Top