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Great price, Quick delivery, the document was very usefull A+++++++++++++++
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Thank´s for your help, I already recived these manual from you
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Thank you for your manual It has the basic things to and i use the Oszi for Longer Time.
THX
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Actually, I was looking for this information for 3 years!...now thanks to you, the manual is on my hands and of great help, cause I understand now where I was doing wrong connections and wires...excellent, I'll be back to you if in need, thank you.
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This manual covers the main equipment features only. While it also includes the procedure for saving and loading from the now long obsolete memory cards it does not mention the how to operate with the optional floppy drive interface so I am still at a loss about how to use this! Note that there is a separate manual covering the MIDI interface and programming via the keyboard, not included in this download. You will also need to get hold of this if you want to use the MIDI interface properly. Basically there is little difference between this manual and the free to download manual for the similar PR60 model.
Model 11153A
Section IV
SECTION IV THEORY O F OPERATION
4-1.
INTRO D UCTlON.
4-7.
CONVERTER AMPLIFIER.
A block diagram of the True RMS Converter is s h q m in Figure 4-1. In the VAC(AC) mode of operation, the input is capacitively coupled; while in the VAC(DC) mode the input is direct coupled, allowing the instrument to measure the total rms value of a signal containing both ac and dc.
4-2. ATTENUATOR AMPLl FIER.
4-3. The Attenuator Amplifier is a broadband inverting amplifier having a differential input stage and a push-pull output stage. Dual field effect transistors used in the input stage are connected as source-followers to maintain a high input impedance. Constant current sources are used at several points in the amplifier to maintain proper bias currents. The Attenuator Amplifier gain is equal to the feedback impedance divided by the input impedance. Range switching is accomplished by varying the attenuation of the Attenuator Amplifier and Post Attenuator as shown in the table given in Figure 4-1.
One half of the dual thermocouple converts the ac signal to dc, and the other half is used in the dc feedback loop of the Converter Amplifier. Since a thermocouple is a non-linear device, the feedback offsets the non-linearity of the amplifier input signal, resulting in a linear dc output. Using the dual unit in this manner also minimizes the effect of ambient temperature drift. An integrating ac feedback loop is employed to filter out the ac component of the thermocouple output. A non-linear amplifier in the ac feedback loop offsets the non-linearity of the thermocouple output to provide a linear integrating action. Integrating capacitance is increased in the VAC(DC) mode to permit measurement of signals down to 1 Hz. The gain of 1 indicated in Figure 4-1 for the Converter Amplifier is the gain from the rms value of the Converter Thermocouple input to the dc output of the amplifier.
4-8. THERMOCOUPLE PROTECTION.
To protect the thermocouple, a virtual short circuit is placed across the Post Amplifier output stage if operating conditions exist which might damage the thermocouple. An integrated circuit comparator amplifier, in conjunction with a bridge rectifier circuit, compares the Post Amplifier output to a predetermined level. If the output exceeds this level, the comparator causes a clamp circuit to shortcircuit the Post Amplifier output stage. A second comparator amplifier compares the output of the Converter Amplifier to another predetermined level, and causes the clamp circuit to cut off the Post Amplifier output stage if the level is exceeded.
4 4 . The Attenuator Guard (shown in Figure 7-1) is driven by an emitter-follower, maintaining the guard at nearly the same potential as the amplifier input. The Attenuator Guard is not connected to the input guard . terminal
4-5.
POST AMPLIFIER.
The Post Amplifier is a broadband non-inverting amplifier gaving a gain of 10. This amplifier also has a differential input stage and a push-pull output stage. The output of the Post Amplifier drives the heating element of the Thermocouple.
4-9.
OUTPUT ATTENUATOR AND FILTER.
4-6.
CONVERTER THERMOCOUPLE.
The Converter Thermocouple is one half of a specially designed dual thermocouple called a thermopile. Each half of the thermopile consists of 30 thermocouples in series, resulting in high sensitivity. The low thermal mass of the thin-fim construction permits rapid response to input signal changes.
The Output Attenuator is provided to adjust the True RMS Converter output to the specified accuracy. The Output Filter is bypassed in the VAC(AC) mode since ample filtering is provided by the 3484A Attenuator Assembly (Al). Because frequencies as low as 1 Hz may be measured in the VAC(DC) mode, the Output Filter is used. In addition, the Filter Amplifier output (from A2) is coupled into the filter to reduce 'response time. The True RMS Converter output is 0 to + 1.5 V on all ranges.
4-1
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