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  1. HellasTechn

    Help select suitable Mosfet for driving relay.

    Yes. It looks very interesting. The 2n7000 can handle up to 200ma instead of the 500ma that the BC337 can. i am not sure why to select that over the BC337. Well it is controlled by the Microcontroller. I write the commant to turn it on and the pin goes from 0V to 5V through a 1K resistor. Now...
  2. HellasTechn

    Help select suitable Mosfet for driving relay.

    Hello ! I want to drive a DPDT relay (FEME LCA 002 12 57) from my arduino mega board. So far i used a BC337 transistor but after running it for a day or two having the relay continuously engaged, i found the transistor shorted. The relay coil will draw 45-50ma and has a resistance of 265 Ohms...
  3. HellasTechn

    Advice about MC34063 based buck converter diagram

    Well i am alredy using the pin's method to connect my boards. I have the arduino board, one Interface board and one I/O board all connected "back to back" so i would like to have the PSU biult in the I/O board and not as separate board. Purely due to my projects design.
  4. HellasTechn

    Advice about MC34063 based buck converter diagram

    Ive been up to my ears with work and i am still. Ill play with it on the breadboard though ! Yes it looks perfect. It's just that i want to build it on my own PCB together with the microcontroller. Actually i have not. It calculates all the values automatically. Super ! I now have enough...
  5. HellasTechn

    Advice about MC34063 based buck converter diagram

    I have no analog signals on the PCB. Should be ok with both.
  6. HellasTechn

    Advice about MC34063 based buck converter diagram

    That looks useful ! So it uses a torroid iron powder core inductor. But i suppose a shielded inductor would be better since the psu will be on the same board with the microcontroller.
  7. HellasTechn

    Advice about MC34063 based buck converter diagram

    I am having trouble finding an appropriate coil for this application. The only information i have is that it needs to be 100uH and be able to handle say 500mA. On the other hand i could slightly modify the values of the components and instead of 100uH i could use a 220uH inductor that can handle...
  8. HellasTechn

    Advice about MC34063 based buck converter diagram

    Thank you Sir ! The specific circuit i am asking for can definitely fit into a 2x2 inch board. Understood. I assume noone has experience with the MC34063 ?
  9. HellasTechn

    Advice about MC34063 based buck converter diagram

    I think i've got the point. I use a TO-220 7805 with a small heatsink on it. the project will be housed into a small ABS plastic box. I am concerned that after hours or days of operation it will turn the box into a miniature oven :p Yes . That is why i am asking for your opinions :) I am not...
  10. HellasTechn

    Advice about MC34063 based buck converter diagram

    Hello to all forum members. I am working an a small project of mine that involves an arduino board and a few relays. My question has to do with the power supply section of my project.- The arduino board needs 5V to run and the relays 12V. I have a 12V 2A switching power supply. My intention is...
  11. HellasTechn

    Good rosin flux paste brands?

    As for solder... I hate using lead free solder. Joints tend to fail alot !
  12. HellasTechn

    Ring Doorbell & Bosch Wifi Thermostat issues

    Well 45%-55% is normal. I dont know what to say... P.S. the surge protector does not really do anything apart from cutting the circuit in case of over voltage (300V or more). If i where you i would check the mains with an oschilloscope for excessive noise. I happen have one because i repair...
  13. HellasTechn

    Ring Doorbell & Bosch Wifi Thermostat issues

    What is the percentage of air humidity ? Maybe that is one factor that causes the problems but what can we say? there may be other also. Mains power is not aways to blame.
  14. HellasTechn

    Looking for LCD Adapter/Converter

    Im sorry, i do not know...
  15. HellasTechn

    Looking for LCD Adapter/Converter

    I am not sure what you want is possible. For example in TV's there are special boards (Tcon boards) that drive the LCD's. Ive never heard of direct connection of HDMI-LCD.
  16. HellasTechn

    Sony Bravia KDL-46Z5100

    What is the exact model number of your TV ? Generally speaking it may be a mainboard issue.
  17. HellasTechn

    Looking for older LED's

    Ok here are the photos of the LED i told you about. It glows red and appears to have a max brightness at 1.8V
  18. HellasTechn

    Looking for older LED's

    I may have some leds you might be interested in. I will post pictures tomorrow if i manage get off work early. P.S. Happy new year.
  19. HellasTechn

    Problem with positive pre-sensitized board exposure solved

    First thing that poped into my mind before i finish reading your post was to get a new lamp :P
  20. HellasTechn

    PCB, Toner transfer method

    Myself i always use the toner transfer method with a small 1000W travel iron for clothes and im printing on magazine semi glossy paper. The printer i use is a samsung m2026. the results are very good (including good quality ground plane). Solder mask is a bit hard if you use the UV paint bit its...
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