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With a max voltage of only 60V, I would try to avoid using IRFZ44N with an operating voltage of 24V DC.
Here's my sim of your circuit using 60KHz 50% pulses and it looks quite acceptable.
You can try with 300Khz and see if that works too...
I used to buy 1/4W leaded resistors from element14. They are in paper tapes and quantity was 50+, 100+, 250+ and 1000+.
I paid about 1 MYR (USD 0.25) for 4 pieces of resistors. I have bought in small quantity of 50 pcs and 100 pcs. Some of the named brands like Vishay were very expensive...
The Tx PCB looks fine to me. I normally would suspect a bad push button. But as you said the LED lights up OK, then it should be fine too.
The inductance are printed on the PCB and I couldn't find datasheet for MC908T and the SAW. Did you do a rough check on Q1 and Q2 BJT to make sure that...
Your RN1 is pulling high with the dipsw also connected to high.
Your RN2 should be 330 ohm instead of 10k.
Still waiting for your program codes. Thanks.
Allen
Here are 3 68HC705 MCU from eBay. 2 of them have quartz windors and the other one does not.
So the one doesnt have is either OTP or EEPROM inside.:razz:
**broken link removed**
https://www.ebay.com/itm/Motorola-MC68HC705C8S-Chip-8-bit-CPU-/401145305993?hash=item5d661f9b89:g:U0UAAOSw9NxTswvF...
Does the 68HC705 has a quartz window for UV to erase the program inside? If not, it is an OTP mcu and can only be programmed once.
Both the 68hc705 and GAL need dedicated programmers. Some universal programmers can program both chips. You can check eBay and major electronics stores for...
I bought this from eBay and mount it on my bike and my friend's bike as well. If you want to make your own customised one, you can keep the guts and use the magnet and reed detector...
I dont have that BASIC so I cant help you. I try your program with PICBasic Pro but looks like PBP doesnt like your program.
My best bet is either get some one who has that BASIC compiler to compile for your or get another similar project that doesnt use Oshonbasic.
Allen
On the link site, it says that he was using Oshonsoft Basic. The Hex file there was also deleted...
So just get hold of a copy of that Basic and compile it.
Allen
Nice work and congratulations. Next step would be designing the display board with display LEDs 10x bigger. ULN2003A should be able to handle the bigger current if each segment not exceeding 60mA.
Allen
Wow, that must be a lot of work designing that PCB.
My only doubt is whether 16F628 has enough program space to do all the stuffs you intended. What is the purpose of the RF transmitter? Should it not be a receiver in case you want to remote control the scoreboard?
The circuit seems OK and it works on the proteus sim. To trouble shoot, I would use a watch to compare the basic clock pulse time from the 4001 osc. is correct.
For easy calculation, I set it to 500mS so what came out from Q3 is 8 second pulse. You have to make sure that this timing is...
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