|
|
| Line 8: |
Line 8: |
| not to damage this connector when assembling or disassembling the units. | | not to damage this connector when assembling or disassembling the units. |
|
| |
|
| An optional component, the P7001 Processing Unit, can be added to a 7704A between the | | An optional component, the [[P7001]] Processing Unit, can be added to a 7704A between the |
| acquisition unit and the display unit. The P7001 has a backplane with an asynchronous | | acquisition unit and the display unit. |
| bus and several cards that plug into that bus: sampler, analog to digital converter,
| |
| memory, and display electronics. Early versions of the P7001 use core memory. Later versions
| |
| use semiconductor RAM. The P7001 assumes a repeating input signal and
| |
| periodically samples the horizontal and vertical
| |
| signals simultaneously. This allows it to fill the memory with data points represented
| |
| as coordinate pairs, (x1,y1), (x2,y2), (x3,y3), etc.
| |
| It is not necessary that x2 be greater than x1.
| |
| The samples can be taken out-of-order with respect to their
| |
| equivalent time in the waveform.
| |
| The signal coming from the acquisition unit enters a fast four-diode sample and hold circuit
| |
| where it is sampled at 150Ksamp/sec.
| |
| Each sample is digitized using a successive-approximation scheme.
| |
| The analog to digital converter is made of several chips:
| |
| a digital to analog converter, a comparator, and control logic.
| |
| The P7001 has its own power supply built into it, independent from the power supply
| |
| in the acquisition unit of the 7704A. The bus is used for low speed signals. High speed
| |
| signals are sent through coaxial cables that connect to the cards using Peltola connectors.
| |
|
| |
|
| The 7704 and 7704A use switchmode power supplies (SMPS). | | The 7704 and 7704A use switchmode power supplies (SMPS). |