Jump to content
Electronics-Lab.com Community


  • Posts

  • Joined

  • Last visited

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

Whizard's Achievements

  1. Should the fan blow the air pass through the heatsink or suck the air from inside the case where the heatsink located?
  2. Anyway, do you have any idea to deal with the thermal solution. The transistors both will generate high power thus they need a heatsink with at least 1°C/W minimum of thermal resistance. The problem now is in my country, it was so difficult to find a proper heatsink with that kind of thermal resistance because the manufacturers here don't know at all about it (or probably just don't care). Do you have any solution for me?
  3. Thanks for your help, I'll try to build this circuit wth 24V 3A transformer and see how it works.
  4. Okay, how about the current sense resistor? For my "30V, 2A power supply" circuit it uses 0.33 ohm 2W resistor for sensing, but your circuit used 0,47 ohm 5W resistor for its sensing purposes. Is there any difference that may affect if I change my 'current sense' resistor with 0,47 ohm 5W like yours?
  5. The old circuit I posted above have included the resistor for the emitter of TR3 (you can see the red marking I made). Should I add more emitter resistor for this output transistor and for the newly added transistor? This is the new design I've made from the old previous circuit. Please take a look.
  6. I have no idea how the parallelized transistors look like. My friends told me to use darlington-pair for a power transistor. I have a schematic of power transistor parallel-configuration for an inveter, here's the picture: Sorry for asking this, but can you show me an example of a parallelized power transistor. Thx in advance
  7. Hi, again thanks for your answer. One more little things here, can you tell me where to add a secondary output transistor for this schematic. I'm really curious to know. Thanks in advance. And also can I use a centre-tapped transformer for producing negative supply voltage? If yes how to place it in?
  8. How did you know that the peak voltage of 24VAC is 40V? Are you measuring it with an oscilloscope or calculate it manually? As far as I know that the formula for determining a peak voltage is by using Vpeak = Vrms x sq root 2. So based on this it must be 33.9V not 40V. isn't it? I'm going to use 100VA/24V, 4.17A transformer for producing 30VDC at 2A safely. What do you think?
  9. What does 'overloaded transformer' means? We knew that current supplied from the windings of a transformer isn't 'pushed' to the load, it's 'pulled' by the load. So I think it's safe to use 2A rating transformer for producing 2A-DC ouput as long as the output isn't overloaded. Can you explain please? Edit: but is it safe to use 3A rating instead of 2A based on your statement above.
  • Create New...