Did You Know...
...Chester Carlson was a patent agent who tired of having to make multiple copies of patent applications using the only duplication method available at the time: carbon paper. In 1959 he came up with a new copying system and took it to IBM for evaluation. The "experts" at IBM determined potential sales to be only 5,000 units because people wouldn't want to use a bulky machine when they had carbon paper. Carlson's invention was the xerography process, the company founded on the system is Xerox.
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| Number | Title | Issue Date |
| 5680302 | AC output control apparatus An inverter for DC/AC conversion includes an inverter bridge controlled by a PWM controller. The inverter has a first control loop for performing PWM control in accordance with the difference between the instantaneous AC value of an inverter output and an... | 10/21/1997 |
| 5519306 | Constant voltage circuit and a stabilized power supply unit A DC constant voltage circuit comprises a rectifier and a boosting chopper circuit controlled by a general purpose PWM control IC. The general purpose PWM control IC receives a reference voltage Vref which regulates the output voltage by pulse width modul... | 05/21/1996 |
| 5111372 | DC-DC converter A DC-DC convertor includes a transformer having a primary winding adapted to be connected in series with a DC power source and a secondary winding, a rectifier and smoothing circuit, a main switching device, adapted to be connected in series with the DC p... | 05/05/1992 |
| 5086381 | DC-DC converter A DC-DC converter includes a transformer and a switching element. The primary winding of the transformer and the switching element are connecting in series with a DC power source. A DC output is extracted via a rectifier circuit connected to a secondary w... | 02/04/1992 |
