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  1. R

    Working out required track width

    Hi all I have a question regarding PCB track width. If i have 1oz copper. I have an external EEPROM connected to my PIC micro via I2C interface. How do i obtain the correct track width and length. I have positioned the EEPROM clise to the PIC to minimise track length. I am using Eagle PCB. On...
  2. R

    Eagle v8.3 PCB tutorial

    Hi Thanks for the reply. Much aporeciated.
  3. R

    Test jig for testing production PCBs

    Hi Thanks for your reply. I have some further questions. Let me take this simple example. I have an smoke alarm PCB that needs to be tested. It has a PIC microcontroller on it. Various LEDs, buzzer, smoke chamber etc I have designed a test bed with pogo test pins that fit into this system and...
  4. R

    Programming c on raspberry pi

    Hi I am looking to program in c on the raspberry pi 3. It comes installed with NOOBS. Do i need to install anything else to get my c programs up and running ie complier or OS. I am a newbie to the raspberry PI so not sure. Thanks in advance.
  5. R

    Eagle v8.3 PCB tutorial

    Hi all I am using Eagle PCB V8.3. I need a good tutorial that covers 1. Creating layers ie 2 or 4 layers 2. How to create keepouts 3. Handling library management especially version control and obsolete parts Thanks in advance
  6. R

    Test jig for testing production PCBs

    Hi all I am looking into designing a test jig that will be used to test populated PCBs off a production line. The PCBs will be microcontroller based with I/O lines connected to LEDs, buzzers, some analogue circuitry too. I need to be able to test each PCB circuit functionality using a test rig...
  7. R

    BJT transistor saturation

    Thanks everyone. Great advice. The information in the link was great.
  8. R

    BJT transistor saturation

    Thanks. I have seen on datasheets information like vce(sat)=0.2v, Ic =10mA, ib 0.5mA. Are these not saturation conditions too?
  9. R

    Wanted: Practical Analog Electronics for Technicians by W A Kimber

    Thanks. I have just ordered it. Much appreciated.
  10. R

    Wanted: Practical Analog Electronics for Technicians by W A Kimber

    Hi all, I am trying to get hold of the following 2 books: Practical Analog Electronics for Technicians by W A Kimber Practical Digital Electronics for Technicians by W A Kimber Does anyone have these that they will be willing to sell? Thanks Raj
  11. R

    BJT transistor saturation

    Yes i have a base resistor of 1k8 in the circuit. Will my calculations saturate the transistor? Also if the transistor was a bc847 npn, can someone show me how to use the datasheet to obtain saturation values for Ic and Ib. Thanks
  12. R

    BJT transistor saturation

    Hi Sorry i was typing in a hurry. I was trying to find out the collector current, base current and value of base resistor to saturate the transistor. Thanks.
  13. R

    Removing DC offset

    I thought tbe offset was due to my voltage divider. Not sure though.
  14. R

    BJT transistor saturation

    Hi all I have a homework question which i would like someone to verify my results please. I have a npn transistor. Rl and Rb are not given. Common emitter configuration. Vcc is 18V. Power is 2W. So using P=VI, transpose this gives me I = P/V = 2/18= 111mA Hfe is IC/IB Note hfe min is 180 Ib is...
  15. R

    Removing DC offset

    Sorry the pk to pk amplitude of the square wave is around 0.9V I was thinking ti remove the voltage divider and have a RC high pass filter ie a differentiator circuit. Having the value of RC less than Time of pulses. Does that seem plausible? Thanks.
  16. R

    Removing DC offset

    Hi Ok thanks for the reply. The diode can be removed. This 9V pulse still needs to be reduced to a level so it doesn't damage the PIC A/D (AN10) line. It will be used to detect the edges of the signal. However the voltage divider has the square wave sitting on a 2V signal. This makes edge...
  17. R

    Removing DC offset

    Hi I have a 9V pulse at 4KHz. This is slighty negative going to about 200mV. I need this fed into a PIC to detect edges. I used a diode to remove the negative oart of the signal. Then fed into a potential divider to divide by a factor of 3. However the output is a square wave sitting on a dc...
  18. R

    Pcb as antenna track

    Hi I am looking to use a HT12E/D with 433MHz RF modules. I have played around with these before. But what I need is the antenna design i.e. the number of turns, type of wire, length etc to get maximum range. Thanks.
  19. R

    Wanted: Everyday practical electronics teach in 2002

    Hi Thanks for the email. I appreciate that you are looking to send the CD with the information. This is my email. [email protected] If you send me a test email, I will then email you my address details. I hope that is ok as I didn't want to post my address details on a public forum. I live in...
  20. R

    Measuring CR123A battery using PIC A/D

    Hi Bob Many thanks for the excellent explanation and taking time to answer my questions. I really do appreciate your help. I clearly understand this now. Best regards, Raj
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