The output of a 555 or a 2 Transistor Bistable Osc. produces a squarewave that sounds like a buzzer. You probably want a mellow sinewave tone so you need a voltage controlled sinewave oscillator.
On the 2 Transistor Bistable Osc. you show a resistor and capacitor not connected to anything. Maybe they are connected to the base of the transistor on the right side as a simple filter that changes the squarewave into a triangle wave.
Later you can add circuits to control the attack and decay of the tones.
I can't understand how your reset works with the diode and 100k resistor. Can you explain your reasoning ?
This is how I would design the unit to work without the timer 555.
View attachment 97650
I have also modified the way the last note is done so you only have one trimmer to set the frequency. The 4017 part of the circuit must be powered all of the time. (It will only consume a few micro amps.) S1 is a push to make button. The 4017 will be in state 7 (After the end of the long sixth note in states 5 and 6) When the button is pressed it resets the 4017 to state 0 so the output of state 7 goes low. this turns on transistor Q1 which supplies power to the rest of the circuit until state 7 is reached which turns off Q1. The maximum current that this transistor can supply is 100 mA so if you need more then the circuit will need modifying.
Note the schematic was drawn with Eagle PCB software which is free. Let me know if you would like the eagle file for the schematic.
Les.
*I can't understand how your reset works with the diode and 100k resistor. Can you explain your reasoning ?
This is how I would design the unit to work without the timer 555.
View attachment 97650
I have also modified the way the last note is done so you only have one trimmer to set the frequency. The 4017 part of the circuit must be powered all of the time. (It will only consume a few micro amps.) S1 is a push to make button. The 4017 will be in state 7 (After the end of the long sixth note in states 5 and 6) When the button is pressed it resets the 4017 to state 0 so the output of state 7 goes low. this turns on transistor Q1 which supplies power to the rest of the circuit until state 7 is reached which turns off Q1. The maximum current that this transistor can supply is 100 mA so if you need more then the circuit will need modifying.
Note the schematic was drawn with Eagle PCB software which is free. Let me know if you would like the eagle file for the schematic.
Les.
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?