摘要 |
A sawtooth voltage oscillator synchronizable by synchronizing pulses, a capacitor being charged and subsequently discharged, between two threshold levels. The oscillator is switchable between two states under the influence of a synchronizing signal detector which establishes the presence of the syncrhonizing pulses, to wit a first state in the absence of the synchronizing pulses wherein the free-running frequency of the oscillator is substantially equal to the nominal repetition frequency of said pulses and a second state in the presence of the synchronizing pulses wherein the free-running frequency of the oscillator is lower than said nominal repetition frequency, the oscillator being thus in its second state synchronizable by the synchronizing pulses. |