2. A system according to claim 1 wherein the constant multiple is two.

3. A system according to claim 1 wherein said fluid is air having a constant volume flow per unit time.

4. A system according to claim 3 further comprising a storage unit for receiving pneumatic digital initiating signals from some signal source, storing indications of the initiating signals for a period of time, and providing the binary pneumatic switching signals.

5. A system according to claim 3, further comprising: A. common storage unit means (30) responsive to a plurality of pneumatic binary input signals (B1-B7) and to a RESET input signal (B8) for receiving said binary input signals, whether they arrive simultaneously or sequentially and temporarily storing data corresponding to said binary input signals, said common storage unit means comprising a plurality of pairs of twin-diaphragm relays (TDR 11 and TDR 12, TDR 21 and TDR 22, TDR 31 and TDR 32, TDR 41 and TDR 42, TDR 51 and TDR 52, TDR 61 and TDR 62, and TDR 71 and TDR 72) connected to form a corresponding plurality of bistable storage devices, the number of said bistable storage devices also corresponding to the number of said binary input signals, one of the twin-diaphragm relays in each said pair being connected to respond to a respective one of said binary input signals, the other of the twin-diaphragm relays in each said pair being connected to respond to said RESET signal, each of said pairs of twin-diaphragm relays acting in correct to provide at the output a corresponding plurality of second binary signals (S1-S7), B. delay means (36) for receiving a delaying a timing signal (B9) to provide at its output a gating signal, C. a plurality of twin-diaphragm relays (TDR 13, TDR 23, TDR 33, TDR 43, TDR 53, TDR 63, and TDR 73) connected to respond as AND-gates to said gating signal and respectively to said second binary signals (S1-S7) to logically generate a plurality of gate-output signals, D. pulse means (34) responsive to said timing signal (B9) to provide at its output a pulse signal, E. memory means comprising a second plurality of pairs of twin-diaphragm relays (TDR 14 and TDR 15, TDR 24 and TDR 25, TDR 34 and TDR 35, TDR 44 and TDR 45, TDR 54 and TDR 55, TDR 64 and TDR 65, and TDR 74 and TDR 75) connected to form a corresponding plurality of second bistable storage devices, the number of said second bistable storage devices also corresponding to the number of said gate-output signals, one of the twin-diaphragm relays in each of these pairs being connected to respond to a respective one of said gate-output signals, the other of the twin-diaphragm relays being connected to respond to said pulse signal, each of said second plurality of pairs providing an output signal from each twin-diaphragm relay in each pair, and F. said pneumatic logic elements being a group of twin-diaphragm relays responsive to both of the output signals from each of said second plurality of pairs.