I have no picture to show what my circuit is like, but I'll try to draw it and explain here as best as possible. The circuit contains a NE555 timer, working in the astable mode with a frequency of 50Khz, 10nF charging/descharging cap, 230 ohm discharging resistor and 2300 +230 ohm charging resistor. It's powered by a single DC supply 15V. So far so good. Powered by the same supply (15V), I have a flip flop circuit, which has no other connection with the 555 timer other than power supply ( which means they share the same ground and same +Vcc, and are not related in any other condition). This flip flop circuit is made by transistors, and it's as follows :
The output is taken from the pnp collector, and the 11k resistor receives a pulse high to turn on, and to be turned off I connect by hand the ground through a wire into the npn's base. The problem is: when the 555 timer is not connected to the 15V power supply, the flip-flop circuit works well as intended, but when the 555 timer is connected, the flip flop circuit goes wild and even by applying a ground voltage to the npn's base it doesn't seem to be turned off as the voltage in the pnp's collector stays high(about 14.5V). What could be taking place here? I really thought of many things but none seem to make sense once they are not connected in any situation but through the same ground and Vcc levels.