CMOS 4060B won't count

Discussion in 'General Electronics Chat' started by abcinc, May 14, 2009.

  1. abcinc

    Thread Starter Member

    Apr 29, 2009
    26
    0
    Circuit is http://uk.geocities.com/ronj_1217/c4060s.html#2

    I have a 360K resistor in place of R3 and R4, C3 is 10uF 16V, R5 is 4.7 meg. Pin 12 (reset not connected but everything else is.

    Issue is no oscilations on pins 9, 10 and 11. I have 12.24 volts DC on pin 16 and gnd is connected to pin 8

    Pin 9 gets constant 50 mv, pin 10 gets constant 12.24 V and pin 11 gets constant 8V all DC. Any ideas? I checked all connections with DVM and checked the resistor values also with DVM.

    Thanks

    Dave
     
  2. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    You need a low leakage (film type) non-polarized (film type) of capacitor for C3.
     
  3. bertus

    Administrator

    Apr 5, 2008
    15,645
    2,344
    Hello,

    The reset should go to ground.(it will not count if this pin is not connected).
    Is C3 a bipolair capacitor (as recomended at the bottom of the picture)?

    Greetings,
    Bertus
     
  4. abcinc

    Thread Starter Member

    Apr 29, 2009
    26
    0
    Ok, the one I have is metal radial 10uF 16 V nichicon B0309. Can you specify a part number?

    Thanks
     
  5. bertus

    Administrator

    Apr 5, 2008
    15,645
    2,344
    Hello,

    It says the capacitor type on the bottom of the picture.

    [​IMG]

    Maplin JA75S , RS 768 728

    Greetings,
    Bertus
     
  6. abcinc

    Thread Starter Member

    Apr 29, 2009
    26
    0
    Maplin JA75S does not exist any more or at least I could not find anyplace localally or internet to buy one.
     
  7. bertus

    Administrator

    Apr 5, 2008
    15,645
    2,344
    Hello,

    The JA75S does exist at Maplin:

    Greetings,
    Bertus
     
  8. Wendy

    Moderator

    Mar 24, 2008
    20,765
    2,535
    You can also take 2X 22µF polarized capacitors back to back to make 1 non-polarized 11µF capacitor.
     
  9. apostilleus

    New Member

    May 15, 2009
    1
    0
    how would the teams feel if they were getting 19:20 instead of 20:00?
    You'd be doing very will to get that degree of acuracy. The large value electrolytic capacitor required for a delay of this lengh would have a high tolerance, typically +-20% so at the worst one team might have 16:00 while another might have 24:00.

    However I do unserstand that you'll be using the same clock for each team so it probably won't be as bad as this but the drift due to temperature fluctuation and aging of the componants will be significant.

    Does anyone have the 555 circuit for minuts? with the value of the capacitor and resistor?
    Look at the datasheet, you'll find that T = 1.1RC, study the graphs, rearange the formula for R, then C and plug different values into it until you get the value of T you desire. Having said this you'll need a trimmer pot for adjustment due to the componant tolerances.
     
Loading...