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  1. HellasTechn

    Serial communication problem.

    Yes i think i have...
  2. HellasTechn

    RS422 to RS232 converter.

    On the breadboard i remove both A+ and A- (or B+ and B-) wires from the chip's input pins. Now i do not. I thought it was not needed. Not more than 20cm total distance from the RS422 transmitter device. No just straight cables. I thought i had uploaded the schematic... sorry, I will upload...
  3. HellasTechn

    RS422 to RS232 converter.

    I guess i could utilise two ua9637 chips (one for each receiver) but that would require more space on the pcb...
  4. HellasTechn

    RS422 to RS232 converter.

    I have been testing the ua9637 chips and i came across a little strange behavior. I use rs422 signal comeing from two GPS receivers. I feed GPS A TO Input A and GPS B to input B (the - and + of each gps output connected correctly to the inputs) now it works just fine but when i disconnect GPS...
  5. HellasTechn

    Serial communication problem.

    Please disregard my previous post. if possible a moderator can delete it ? Thank you !
  6. HellasTechn

    Serial communication problem.

    I have this question... For my Picaxe project i want to tap my picaxe to the rs232 line so that it can "snif" data. The problem with the circuit in post #61 is the diode that protects the transistor from reverse voltages. when rs232 line is -15V That diode pulls my rs232 line to ground...
  7. HellasTechn

    Yamaha RX-V675 stopped working after thunderstorm

    It could be an error stored in the CPU that is causing this. Try the reset procedure to see what happens: 1. Set the unit to Standby by pressing the Power button. 2. While holding down the Straight button, press the Power button. 3. SP IMP. 8 Ohm Min (Or 6 ohm) will come up on...
  8. HellasTechn

    Success at last

    You could use Mica pad for to-220 with plastic washer and bolt with nut. like this one: https://www.ebay.co.uk/itm/20-x-Thermal-Insulator-Kit-Mica-Pad-Bush-Washer-for-TO-220-Heatsink-/182897625502 You can also find them on the heatsinks of old computer power supplys.
  9. HellasTechn

    Success at last

    Aren't the BD139 plastic ?
  10. HellasTechn

    Serial communication problem.

    Is it a software simulation or does it actually transmitts the text through the PC's rs232 port ?
  11. HellasTechn

    Serial communication problem.

    Thank you so much for your usefull information ! I will give it a try and let you know. I am downloading it as we speak.
  12. HellasTechn

    Success at last

    Well, Its normal to make mistakes and blow a few instruments and destroy a few boards... Who has not done that as a beginner ?
  13. HellasTechn

    Serial communication problem.

    Yes i am at this point a while now since i havent had the slightest idea about programming before i came across Picaxe. Seriously now i really dont know a thing about programming besides the very basic commands of Picaxe. I take your word for Great Cow Basic. I will try it and see.
  14. HellasTechn

    Success at last

    This story reminds me of myself... Never i had started a project and had sucess right from the beginning. Anyway the DMM's have a small fuse inside. You should check it before you throw them away. Also you should buy one of theese... I can not live without it anymore ! it measures...
  15. HellasTechn

    Serial communication problem.

    I am not familliar with this expression. :) what does it mean ?
  16. HellasTechn

    Serial communication problem.

    I am away for the weekend so i will try it i a few days. I will write back to let you know. It looks like it will work for me. Thank you so much ! :)
  17. HellasTechn

    Serial communication problem.

    I apologise for the long time it took me to write back... I will try to explain the best way i can. I beleave you remember my Picaxe-GPS project. In my lab i do not happen to have the two GPS receivers i need to perform a real time test with the picaxe. I need the serial terminal to be able...
  18. HellasTechn

    PIC18 Serial Communications

    Or re assign the pins if it is not to hard to alter the code accordingly ?
  19. HellasTechn

    Yamaha receiver won't turn on

    I repaired a Yamaha RX-V795a about 6 months ago. I cant really remember what was wrong with it. One thing i do remember is that there was a problem with the fan running at very low rpm and the amp was overheatig. I The protection kicks in if something is wrong in a number of places on the...
  20. HellasTechn

    Serial communication problem.

    I know it turned ito a spaggeti bowl ! What i need is a general purpose terminal app. Termite serial terminal is a n excellent tool, what i need more is to be able to write the text and the software to keep repeating it until i stop it. Anyway i am trying to do this with hardware (picaxe...
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