The electronic measuring device "shop" is a universal tool for the work of not only radio engineers and electricians. It can be successfully used by anyone who is accustomed on their own to eliminate electricity-related problems in the house. Today, such devices are available to everyone. They are available both in analog (switch) and digital versions. In Soviet times, the Ts-20 device and its analogues were such an indispensable assistant.
What is a "workshop", what measurements can be made
The Ts-20 device is the most famous Soviet multimeter. It was designed to measure the following values:
- Current strength.
- Voltage values of constant polarity.
- Sine-wave AC voltage with a frequency of 50 Hz.
- Resistance to a direct current.
The device allows you to measure the declared parameters of electricity in the following limits:
- For a constant current, the range is from 0 to 0.30 mA, 0–3.00 mA, 0–300.00 mA, 0–750.00 mA.
- For a constant voltage range: 0 to 0.60 V, 0–1.50 V, 0–6.00 V, 0–120.00 V, 0–600.00 V.
- For AC voltage, the range is from 0.60 to 3.00 V, 1.50–7.50 V, 6.00–30.00 V, 0–120.00 V, 0–600.00 V.
- For resistances, the range is from 5 to 500.00 Ohms, 0.05–5.00 kOhms, 0.50–50.00 kOhms, 5.00–500.00 kOhms.
The device has a measurement error, which for current and voltage lies within 4%, and for resistance within 2.5%.
Features of the Ts-20 multimeter
Universal device "shop" is arranged quite simply. It is placed in a carbolite (for older models) or a plastic case. On the front panel there is an indicator in the form of a dial electromagnetic scale. Under it there are control knobs and a group of connectors for connecting wires with test probes. Everything is signed here, so it’s easy to learn how to ring the multimeter with a multimeter.
Circuitry "shops" can be divided into main blocks:
- Straightening.
- For measuring constant and variable voltage values.
- For measuring constant current values.
- To measure resistance.
- Display unit
Each of them has its own characteristics.
Blocks for measuring current and voltage contain a set of quenching resistors. Each of them can be connected in turn to the circuit. It depends on the measurement limit. The greater the value of the measured electricity, the greater the resistance of the circuit. Further, the canceled current is supplied to the dial indicator.
The rectifier unit converts the alternating current to direct when measuring the alternating voltage. Switching between measurement modes is carried out by a switch.
The resistor measuring unit also includes a set of resistances, but they serve as additional elements. For the functioning of the Ts-20 ampervoltmeter in this mode, the circuit provides an additional power source for chemical elements.
Location and purpose of controls
The Soviet multimeter provides only two controls located under the dashboard:
- Knob for switching operating modes.
- Zero position knob for the indicator arrow.
The first is implemented on a multi-position switch that switches between each other:
- Block 1 and an indicator unit (DUT) directly for measuring constant voltage values.
- Block 1 and DUT through a rectifier block for measuring variable voltage values.
- Block 2 and DUT directly for measuring direct current.
- Block 3 and DUT directly for measuring resistance.
In each particular mode, other switching capabilities are disabled. Therefore, it is not difficult to figure out how to use the "workshop".
The arrow adjustment knob only works in resistance measurement mode, since in this case an additional power source is connected to the indicator.
The device is also equipped with a pair of probes for connection to the measured circuit. It’s easy to deal with their connection, as a group of connectors is located on the bottom panel of the device, each of which is signed according to the maximum permissible value.
Voltage measurement
This process is not complicated, but requires care. When measuring the value of constant voltage with a "workshop" device, the following algorithm of actions is performed:
- The black probe is connected to the common output (indicated by an asterisk on the case), and the red probe is connected to the connector to the specified measurement limit under the + V icon.
- Turn the knob for switching the measurement mode in the direction of the sign "constantly".
- Connect the probes to electricity with a common output to minus, and the other (red) to plus.
- Take measurements.
In order not to burn the device "shop", the measurement limit is chosen in a larger range than the measured voltage. If during measurements the position of the arrow is at the beginning of the scale, then the limit is lowered (focusing, of course, on the magnitude of the result). More accurate readings are obtained when the needle is on the second half of the scale.
When measuring AC voltage, use the limit connectors under the “~ V” icon. The mode knob is put on the “~” icon. All other actions correspond to the points described below.
Current Definition
When measuring DC current, it’s also not difficult to understand how to use the “workshop”. Actions should occur in the following sequence:
- The black probe for measurements is connected to the common output, and the red probe is connected to the output to the specified measurement limit under the + mA icon.
- The mode dial must be in the “-” position, which corresponds to direct current.
- The circuit in which it is necessary to measure the current is broken. A multimeter (serial connection) is included in this gap. The polarity of the connection is as follows: “+” line break - “common” probe of the device - “positive” probe - load output.
- Take readings.
It is important to remember that the "workshop" is designed to measure small constant currents.
Multimeter circuit and resistance measurement
Measurement of the resistance value by the device is as follows:
- The first probe is connected to the common output, the second to the connector (choosing the correct limit) under the "rx" icon.
- The mode knob is also moved to the "rx" position. At the same time, an additional power source is included in the circuit.
- The dial “0” moves the arrow to the zero position on the scale.
- The probes are connected to a resistance whose rating must be measured.
- Take readings.
Taking measurements directly in the circuit, one of the resistance leads must be soldered. Otherwise, it can be shunted by another element. Because of this, the readings will be incorrect. It is also possible to easily disable field effect transistors, if any, in the circuit.
To simply ring the integrity of a conductor with a multimeter, the probe is connected to the "x1" terminal, after which they look at the scale. With a whole conductor, the resistance will tend to zero. If there is a break, then the resistance will gravitate to infinity.
Advantages and disadvantages of the device
The advantages of the "workshop" include the simplicity of its execution and work. The disadvantage of the device is that the error of the switch equipment is somewhat greater than the electronic.
Conclusion
It should be noted that for each measurement mode the display has its own scale. For currents and voltages, readings are counted from right to left, and vice versa for resistances. For the latter, you need to multiply the result by the number indicated in front of the probe connector.
It is always important to remember that before using the multimeter, you must comply with all safety rules regarding electrical operations!