how to construct a mod-60 stopwatch counter?

goblin85

Jan 5, 2005
2
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Jan 5, 2005
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2
anybody can help me out with this?
using:
1 - 74LS74 (D-type flip flop)
2 - 74LS93 (4-bit binary counter)
1 - 74LS32 (OR gates)
1 - 74LS00 (NAND gates)

construct a mod-60 counter, the BCD will count the numeric sequence from 00 to 59 and it will reset back to 00, by having a mod-10 & a mod-6 counter, to make it. where by having a Stop/Start switch & a Reset switch.

Sombody please help me. thanks

 

audioguru2

Apr 6, 2004
12,026
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Apr 6, 2004
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12,026
Nobody uses old fashioned TTL logic ICs anymore. Can you buy them anywhere?

 

E12

Dec 12, 2017
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Dec 12, 2017
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Yes, you can buy basic TTL Chips from Digikey or Amazon. BTW here is the closest I could build up to your specs. I did not use the 7432 OR gate though. Just made a 5 input 7400 NAND gate. When the output of x1 x2 x8 x16 x32(∑=59, because the base10 is one less than the MOD# ie mod#-1=Base10) goes active HIGH  activates all the AND gates to go High. When this happens it activates the NAND gate to be a LOW state. This causes the clear inputs of the 7476 JK flip-flops to clear and start the count at 0.

Also, please note that the least significant bit(LSB) is on the left, and the Most significant bit (MSB) is on the right.

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HakimJacob

Jan 6, 2021
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Jan 6, 2021
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Hi...what are you utilizing for a clock? I expect you are utilizing the MR1 and MR2 contributions to execute your Mod n usefulness. The 74ls32 can be utilized to likewise permit an outer sign (reset switch) or the information signs to reset your chips. You can disconnect the principal flip lemon of the 'ls93 utilized for the Mod 6 counter and use it as a hook for start/stop, since you just need the last three yields for Mod 6. This hook can be utilized to door the clock into the Mod 10 counter. You have the 'ls00 for gating the clock beats.

turnkey prototype assembly

 
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