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Why is this circuit not working ?

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madhavdivy

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I have attempted to build a toggle switch with D Flip flop 4013, - refer to my ckt attached in pdf.

I have simulated the pulse train (Fin = 2 hz) with NAND gates (4093 - schmitt - clear edges) in astable mode (LED 1 as indicator) and this goes as input to CLK of D FF.

The inv. Q output is connected to D input.

I have put a transistor with a 2.2 k resistor in between the base of transistor 2N2222 and the Q output of CD4013. This is for indication of (Fin/2) with LED 2 with 1k current limiting resistor in the collector.

All unconnected pins have been connected to GND. The entire circuit is being powered by a single switch and DC of 11.12 v.

Can you show some way, as the output is getting latched to single position, even though LED 1 is flashing at the determined rate. Thanks in advance.
 

mister_rf

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No loose wires in the circuit?
Did you use the pins Qinv and Din from the same flip-flop? (Not to mix wires :grin: )
 

ud23

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what is your connection for reset and set pin they should be grounded then u get output otherwise all output go high.
 

madhavdivy

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@mister_rf:

positive, checked and rechecked. no loose wires. no dry soldering, touched up all junctions again. Even changed the IC. Yet the outputs are latchd to their respective states (Q = 0 & Q/ = 1).

@ud23:

Reset has a resistor (100 k) to Gnd and a capacitor (0.1uF) to +12v. Set is connected to Gnd.

I want this to convert the momentary output from the D0 - D7 pins of TXD - 433 - KH2 (Linx) to latched contacts (potential free) vide relays. These potential free contacts drive my VFD for remote start / stop / forward / reverse / increase / decrease speed of my RC robot.

I also need to get an idea on the pulse width of D0 - D7. I shall post the same in RF section.

Thanks for the response.
 

ud23

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i am asking about of ic 4013 set and reset pin no.6 and pin no.4 respectively are they grounded?and how you very your input to D.
 

Embedded_Geek

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ic 4013 datasheet can help you out in this. I have used it before.
 

madhavdivy

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@ud23:

The reset pin (pin 4 of 4013) is connected to a resistor and capacitor. Other end of the resistor is to GND and the other end of the capacitor is connected to +12v. This is for ensuring that the output starts low when powered.

the set pin (Pin 6 of 4013) is connected directly to GND.

@ajishgopalr:

Can you please post the circuit you have employed earlier and oblige?

thanks for the help.

---------- Post added at 17:53 ---------- Previous post was at 17:52 ----------

@ud23:

The reset pin (pin 4 of 4013) is connected to a resistor and capacitor. Other end of the resistor is to GND and the other end of the capacitor is connected to +12v. This is for ensuring that the output starts low when powered.

the set pin (Pin 6 of 4013) is connected directly to GND.

@ajishgopalr:

Can you please post the circuit you have employed earlier and oblige?

thanks for the help.
 

ud23

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The reset pin (pin 4 of 4013) is connected to a resistor and capacitor. Other end of the resistor is to GND and the other end of the capacitor is connected to +12v. This is for ensuring that the output starts low when powered.

I think as far as i know you can set your out put low when powered this arrangement can be done by your software or the way you giving input create your logic that way that you can get initial output as low i think u can try with reset pin directly GND and change in software it should work according your requirement.
 

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