Recent content by FireFly3

  1. FireFly3

    0-30 Vdc Stabilized Power Supply

    I started collecting the parts for this project quite some time ago and then got sidetracked with other things.
  2. FireFly3

    Cuckoo Sound Generator PCB

    Anyone happen to have a pcb image for this project that they would like to share? Thanks.
  3. FireFly3

    Displaying amps & volts on 1 display

    I was looking at the datasheets for the Maxim ICL7135 4 1/2 Digit ADC and the ICM7211 4 Digit LCD Decoder Driver: http://pdfserv.maxim-ic.com/en/ds/ICL7135.pdf http://pdfserv.maxim-ic.com/en/ds/ICM7211-ICM7212.pdf I'm still a little (actually alot!) baffled by the various display interfaces...
  4. FireFly3

    0-30 Vdc Stabilized Power Supply

    Sorry about my 2 previous posts. Please ignore my stupidity. I'm going back to bed now!
  5. FireFly3

    0-30 Vdc Stabilized Power Supply

    Sorry. My last post should have said 450v caps rather than 250V caps.
  6. FireFly3

    0-30 Vdc Stabilized Power Supply

    I'm aware that the filter cap is recommended to be much larger uF wise but I'm wondering about the voltage rating. The original part list called for a 50V cap. I may have found some large-enough, 250V caps. Would using caps with much higher voltage ratings do anything good or bad to this...
  7. FireFly3

    0-30 Vdc Stabilized Power Supply

    And one more substitution please: 2N2219 I can't seem to locate these in a form easily attachable to a heat sink. Can someone suggest another model(s) suitable for this circuit that would be easier to find in a "heat sink form" such as TO-220? Thanks again (for the umteenth time!)
  8. FireFly3

    0-30 Vdc Stabilized Power Supply

    Could some one tell me if TI's 44V TLE214x op-amps would also be a good substitute for the TL081. I haven't got a complete handle on what all the specs mean yet. Thanks. Datasheet: http://focus.ti.com/lit/ds/symlink/tle2141a.pdf
  9. FireFly3

    When to use a heat sink

    Thank you, MP. Sounds like 3/4 experience and 1/4 mathematical. The heat sink(?) I was referring to in the picture is the black "collar" towards the upper right of the board right beside where the 3 2N3055 connection wires attach to the board. Isn't that the Q2 = 2N2219 and a little, round...
  10. FireFly3

    When to use a heat sink

    I was looking at various datasheets for bridge rectifiers for the "0-30 VDC STABILIZED POWER SUPPLY" project. I'm trying to understand when a heat sink is required. For example, the datasheet for the NTE5329, 6A bridge rectifier: http://www.nteinc.com/specs/5300to5399/pdf/nte5329_31.pdf...
  11. FireFly3

    Data Sheet K818, K819 and BD705, BD708

    Does this NTE cross reference give you what you want: http://nte01.nteinc.com/nte/NTExRefSemiProd.nsf/$$Search?OpenForm It comes up with an NTE equivalent for each one you listed and maybe you can get the specs from the NTE part datasheets? Does that help? Sorry if this isn't what you...
  12. FireFly3

    Bridge Rectifier Selection

    I've been looking into selecting a one-piece square bridge rectifier for the 30V/3A power supply project. There seems to be lots of these like every other component type! Generally, they seem to have rather heavy voltage/amperage handling abilities. What is the downside to using a bridge with...
  13. FireFly3

    "Snap-in mount" capacitors

    While looking over some big capacitor specs on the NTE site, I came across what they call Snap-in mount. Can these be used with a board I create myself? Is there some kind of connector that I would attach to the board and then the capacitor attaches to that? Or what...?
  14. FireFly3

    Convert 0-30V 3A PSU to 5A or more

    I've almost collected all of the parts I need for the original 30V/3A project. A new, old-stock, Hammond 25V/5A transformer will be arriving any day now. I've got the presinsitized board, chemicals, etc. and have added extra points to drill to allow meter attachment (someday!). But I don't...
  15. FireFly3

    Convert 0-30V 3A PSU to 5A or more

    Thank you very much for your previous posts on the component sizes and issues. I just want to make the original 30V/3A supply reliably live up to its specs! Just so I understand would you please answer the following. For the original 30V/3A supply: Transformer should be about 4A to 5A...
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