Abstract: In a push button operated telephone set to be used in a telephone system designed for break/make impulsing an electronic circuit is used for converting the push button signals to break/make pulse trains. In order to supply power to the electronic circuit from the central battery through the subscriber's line even if the terminal voltage is low at the subscriber, a DC voltage converter is used in the set to multiply the terminal voltage. This converter includes a pulse oscillator which is also used as a timing pulse generator for the electronic circuit, controlling the frequency, make/break ratio and pulse sequence intervals of the dial pulse trains sent to the exchange.