Search results

Search Forums New Posts
  1. WHONOES

    Temperature controllers?

    If you decide to got the thermocouple route then I would advise you to get something ready made. Interfacing with a thermocouple is no mean feat. There are various types, all are non linear and there is the complication thermal emf's at the point of connection to your circuit which would require...
  2. WHONOES

    Help identifying component

    You could always use a solder tag to accommodate the wire or even make one from a bit of brass , copper or tinplate strip.
  3. WHONOES

    UM66 is not giving full tone

    You could use a 555 timer that is initiated by the bell push to supply the BT66 part of the circuit. The 555 period can then be set to play the entire repertoire.
  4. WHONOES

    Interfacing a NTC thermistor to a PIC

    Absolutely right, a constant current source would indeed improve linearity, it just depends on how accurate Rajinder needs it to be. Hopefully he will tell us.
  5. WHONOES

    Interfacing a NTC thermistor to a PIC

    I like your follow up to my suggestion for using a PRT. It would be possible with a small mod to remove the influence of the offsetting on the gain.
  6. WHONOES

    Interfacing a NTC thermistor to a PIC

    Using a PRT, it would be very straight forward. As they are linear over the temp range you quote, it would just need a bit of straightforward scaling with an opamp to provide an output compatible with you chosen pic.
  7. WHONOES

    What is this ic for?

    Why don't you do a search on google and see what it turns up.
  8. WHONOES

    Interfacing a NTC thermistor to a PIC

    What temperature range do you want to monitor?
  9. WHONOES

    Interfacing a NTC thermistor to a PIC

    You could use a Platinum Resistance Thermometer (PRT) instead. They are very linear and come in 100Ω or less commonly 1KΩ resistances. These quoted values are for when the element is at 0 deg C. They are a bit more expensive than your proposed NTC's or PTC's but, would not require any complex...
  10. WHONOES

    Event tria channel went out

    Start by looking at the power supply voltages. Do a like for like check i.e. turn on the known working unit and use a DMM to measure PSU volts all referenced to 0V (assuming it is a split supply) then replace the transformer in the non working unit and switch on. If smoke doesn't try to escape...
  11. WHONOES

    Help how to calculate a LED wall 10 M2

    The current draw mentioned is from the mains. Which means that just over 1kW is available at 230V which should be enough for his 800W panel. Rmschtt seems to have misunderstood what was said and thinks that he needs to be able to draw more than 80A from his mains supply.
  12. WHONOES

    Help how to calculate a LED wall 10 M2

    From the mains supply aspect you will only need to draw a maximum (with some headroom) of 4.5A at 230V. Easily achievable. See the attached link. There are a number of ready made supplies for you exact purpose. http://www.0meter.com/products?category=7
  13. WHONOES

    Need help finding power supply

    If the transformer has indeed failed, it will be very specific to that particular power supply. If so, the only solution if the manufacturer will not supply a replacement which they probably won't, will be to re-wind it. Have you checked to see if the switching transistor is working?
  14. WHONOES

    Bicycle generator

    Arghh, the end of the planet as we know it???????????????
  15. WHONOES

    Li ion battery charger, adapting power bank

    Charging your battery is not as straightforward as it may first appear. As you correctly say, fire could ensue. You need to limit the charge voltage to 4.2V and limit the current to about 1/4 battery capacity or less.
  16. WHONOES

    Li ion battery charger, adapting power bank

    Can we safely assume that the battery in question is a Li-Po?
  17. WHONOES

    Can I use resistor instead of pot with LM386?

    Putting a trimpot as per VR1 does not adjust the gain off the amplifier. It's gain is set internally to 20. VR1 just adjusts the input level.
  18. WHONOES

    Can I use resistor instead of pot with LM386?

    Using a 10K resistor instead of a pot will work fine. A fixed resistor of ant value(within reason) will not affect the gain of you LM386. The only effect of using different values would be the roll off frequency from its combination with C1. As an aside, I don't like the way the wiper of VR1 is...
  19. WHONOES

    What do you call something...

    Try searching "Fibreglass sheet" on ebay. I got loads of hits.
  20. WHONOES

    Newbie Intro

    I suggest that you buy a copy of "The Art of Electronics" by Paul Horowitz. Most engineers have a copy.
Top