Hi Everyone
I was studying binary the other day and came across a binary clock. It uses BCD (Binary Coded Decimal) to display the time. I thought that this was a really novel idea and would be an ideal little project. I searched Google and sure enough I was able to find a schematic for one.
I will be working at a summer camp for a few months in the summer, delivering classes in electronics and thought this would be an ideal project for the more advanced students. So I set about studying the circuit and "attempting" to tweak the circuit a little to meet my needs... this apparently was a little more dificult than I first anticipated. I would direct my questions directly at the author of the wonderful website that I got the circuit from Bill Bowdens Hobby Circuits however when I tried to contact him, the email just bounced straight back.
Please FOLLOW THIS LINK for information on the circuit that I'm discussing.
So anyway... enough of my rambling and actually onto my questions:
Looking forward to hearing from anyone, any help is much appreciated!
Kind Regards
Edward
I was studying binary the other day and came across a binary clock. It uses BCD (Binary Coded Decimal) to display the time. I thought that this was a really novel idea and would be an ideal little project. I searched Google and sure enough I was able to find a schematic for one.
I will be working at a summer camp for a few months in the summer, delivering classes in electronics and thought this would be an ideal project for the more advanced students. So I set about studying the circuit and "attempting" to tweak the circuit a little to meet my needs... this apparently was a little more dificult than I first anticipated. I would direct my questions directly at the author of the wonderful website that I got the circuit from Bill Bowdens Hobby Circuits however when I tried to contact him, the email just bounced straight back.
Please FOLLOW THIS LINK for information on the circuit that I'm discussing.
So anyway... enough of my rambling and actually onto my questions:
- I understand that the 60Hz frequency is derived from the mains, however I would like to power the clock from a 9V PP3 battery, therefore I'm looking to use a crystal instead, but struggling to work out how? I've read about using a crystal combined with a 4060 instead of a 4040 chip?
- I was thinking of using something like a 7805 voltage regulator to get the correct power for the chips, would a 0.1A model be suitable or maybe the larger 1A version?
- Would the resistors for the LEDs need adjusting at all and would it be ok to use a commoned SIL resistor package for the hours, minutes and seconds instead of 19 individual resistors?
- How could I make it 24 hours? I presume I need to add another LED to the hours 74HC390 as there is only 5 on that one currently and 6 would be needed. Although I'm struggling to understand how the 1N914 diodes work for the 13th count that is mentioned in the accompanying text.
- I'm assuming that the lines connecting pins 3+4, 7+15, 12+13 on the 74HC390 are links between the pins on the chip? I've never seen a schematic before that has wires going over chip symbols.
- Does anyone have any experience/tips in manufacturing double sided PCBs? I have made single sided ones before using the photographic method (UV Light Box and Tri-tank, develop, wash and etch unit.)
- One final question... for now at least! I am struggling to get the CD4040 - 12 Stage Binary Counter and also the CD4071 Quad OR gate, will a 74HC4040 and also 74HC32 be suitable replacements?
Looking forward to hearing from anyone, any help is much appreciated!
Kind Regards
Edward