DM504A: Difference between revisions

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{{TM500 | mfg=Tektronix | type=DM504A | function=autoranging digital multimeter | class=multimeter | image=Tek dm504a.jpg | introduced=1989 | discontinued=(?) | an=an |
{{TM500 | mfg=Tektronix | type=DM504A | function=4½ digit autoranging digital multimeter | class=multimeter | image=Tek dm504a.jpg | introduced=1989 | discontinued=(?) | an=an |
designers=  
designers=  
|manuals=
|manuals=
* [[Media:070-6945-00.pdf|Tektronix DM504A Manual]]
* [[Media:070-6945-00.pdf|DM504A Operator Manual 070-6945-00]]
* [[Media:070-7135-00.pdf|DM504A Service Manual 070-7135-00]]
{{ROM Images}}
* [[Media:160-5426-05.bin|160-5426-05]] / [[Media:160-5426-03.bin|160-5426-03]] / [[Media:160-5426-00.bin|160-5426-00]] (27C64) ''please add''
}}
}}
 
{{BeginSpecs}}
 
{{Spec | DC Voltage    | 200 mV to 1000 V in decade steps, ±0.05%; Input resistance 10 MΩ (200 kΩ in 0.2 and 2 V ranges if V<sub>in</sub> >12 V) }}
==Specifications==
{{Spec | AC Voltage    | 200 mV to 500 V in decade steps, ±0.6%; Input resistance 10 MΩ // 100 pF }}
 
{{Spec | DC current    | 200 μA to 2 A in decade steps, ±0.1% }}
* 4-1/2 Digit Autoranging DMM
{{Spec | AC current    | 200 μA to 2 A in decade steps, ±0.6% }}
* True RMS AC Functions
{{Spec | Resistance    | 200 Ω to 20  MΩ in decade steps, 0.05% (0.1% in 2 and 20 MΩ ranges }}
* Modes: DC Volts, AC Volts, DC mA, AC mA, Ohms, and Temperature  
{{Spec | Temperature  | −62 °C to +230°C with [[P6602]] 2-wire PT-100 probe }}
* 0.07% DC Voltage Accuracy
{{Spec | Display      | 4½ digits, red LED, 2/s update rate }}
{{Spec | Features      |
* Modes: DC Volts / mA, AC Volts/ mA (True RMS), Ohms, and Temperature  
* Diode Test and Audible Continuity (Beeper) Modes
* Diode Test and Audible Continuity (Beeper) Modes
}}
{{EndSpecs}}


==Links==
==Links==
* [http://www.barrytech.com/tektronix/tektm500/tekdm504a.html DM504A @ barrytech.com]
* [http://www.barrytech.com/tektronix/tektm500/tekdm504a.html DM504A @ barrytech.com]
* [https://youtube.com/watch?v=b-xhF_-hiqM DM504A repair] by VintageTEK Museum @ YouTube
{{Documents|Link=DM504A}}
==Internals==
The DM504A has no rear interface I/O. The entire circuit is supplied from a +12/−12/+5 V floating power supply that uses a small mains-frequency transformer fed by one of the mainframe's 25 V<sub>AC</sub> windings.
The circuit is based on an [[Intel 8031|80C31]] microcontroller with a Texas Instruments TL500C integrating A/D front-end and a 1N827 temperature-compensated zener reference.  The DM504A is software-calibrated, storing cal constants in a 93C46 EEPROM.  Calibration is triggered by pressing Up and Down buttons simultaneously while the internal cal jumper is in the "enabled" position.


==Pictures==
==Pictures==
Line 26: Line 40:
Tek-DM-504A-RH_Interor-No_Shield.jpg | DM504A RH Interior with HV shield removed
Tek-DM-504A-RH_Interor-No_Shield.jpg | DM504A RH Interior with HV shield removed
</gallery>
</gallery>
==Components==
{{Parts|DM504A}}

Latest revision as of 04:06, 1 August 2024

Tektronix DM504A
4½ digit autoranging digital multimeter
Tektronix DM504A

Produced from 1989 to (?)

Manuals
ROM Images
File Pos. Checksum
(All manuals in PDF format unless noted otherwise)
Manuals – Specifications – Links – Pictures

The Tektronix DM504A is an 4½ digit autoranging digital multimeter plug-in for the TM500 system.

Key Specifications

DC Voltage 200 mV to 1000 V in decade steps, ±0.05%; Input resistance 10 MΩ (200 kΩ in 0.2 and 2 V ranges if Vin >12 V)
AC Voltage 200 mV to 500 V in decade steps, ±0.6%; Input resistance 10 MΩ // 100 pF
DC current 200 μA to 2 A in decade steps, ±0.1%
AC current 200 μA to 2 A in decade steps, ±0.6%
Resistance 200 Ω to 20  MΩ in decade steps, 0.05% (0.1% in 2 and 20 MΩ ranges
Temperature −62 °C to +230°C with P6602 2-wire PT-100 probe
Display 4½ digits, red LED, 2/s update rate
Features
  • Modes: DC Volts / mA, AC Volts/ mA (True RMS), Ohms, and Temperature
  • Diode Test and Audible Continuity (Beeper) Modes

Links

Documents Referencing DM504A

(no results)

Internals

The DM504A has no rear interface I/O. The entire circuit is supplied from a +12/−12/+5 V floating power supply that uses a small mains-frequency transformer fed by one of the mainframe's 25 VAC windings.

The circuit is based on an 80C31 microcontroller with a Texas Instruments TL500C integrating A/D front-end and a 1N827 temperature-compensated zener reference. The DM504A is software-calibrated, storing cal constants in a 93C46 EEPROM. Calibration is triggered by pressing Up and Down buttons simultaneously while the internal cal jumper is in the "enabled" position.

Pictures

Components

Some Parts Used in the DM504A

Part Part Number(s) Class Description Used in
AD737 156-3506-00 Monolithic integrated circuit RMS/DC converter DM504A
Intel 8031 Monolithic integrated circuit 8-bit microcontroller 11A33 571 DM504A DM511 DM5110