Electronic Design

Introduction

The CB series represents two-wire transmitters with a current loop. The CB-30 Series works with milliVolt and Volt signals. Both series are isolated single channel transmitters that amplify, filter, isolate and convert the voltage signal from the sensor to an output current of 4 to 20 mA. They are suitable for transmitting signals up to 1200 m to the data acquisition system, industrial PC, PLC or some other measuring system.

CB-30 insulating power transmitters protect people and measuring equipment and physically separate them from ecstatic events that may appear on the sensor side or somewhere else within a measuring environment. Both the input and output of the module are protected from transients and voltage levels up to 250 Vrms. Transmitters have a very low price and excellent features that are encountered only in very expensive devices.

CB transmitter families have a chopper input amplifier with low temperature drift, low offset and very stable gain coefficient. The amplifier is determined by two precise voltage references. The transmitter operates on the principle of amplitude modulation and transformer isolation of the signal so that the primary side of the module is "floating" in relation to the secondary side of the module. This architecture gives excellent linearity, stable and reliable characteristics and does not require input grounding. The signal demodulator on the output (secondary) side of the module restores the original signal, which is then filtered and converted to a 4 to 20 mA current signal.

Attributes

Instrumentation accuracy, linearity, repeatability and reliability
Voltage (mV and V) input levels
Isolation from 1500 Vrms
Output: 4 to 20 mA
Accuracy ± 0.03%
Linearity ± 0.01%
NMR 80 dB (50 Hz)
CMR 160 dB
Power supply of the conditioner from 11 V to 60 V through the current loop
The input and output are continuously protected up to 250 V
Frequency range 3 Hz, 3 KHz and 10 KHz (-3 dB)
Easy installation on DIN rail
The warranty period is 7 years, and the service period is 10 years

Block diagram of CB-30 isolation transmitters

Characterization

The input circuit provides protection against incorrectly connected voltages up to 250 VAC and protection against transients defined by ANSI / IEEE C37.90.1-1989 documents. The transmitters have a fifth-line filter, which suppresses 50 Hz with 80 dB (min. 10,000 times). An Anti-Aliasing Pole Filter (LPF) is located in the primary circuit of the module, while on the secondary side of the isolation barrier there is a fourth-order filter. After the Anti-aliasing filtering on the input side of the conditioner, the signal is applied to the chopper level behind the insulating micro transformer. The signal transmission method is amplitude modulation. This technique provides better results than the technique with linear opto-scanners or capacitor isolation techniques. In the secondary stage, behind the isolation barrier, the signal is demodulated and filtered again from the transmission interference.

The power supply of the transmitter is via a power loop in the range of 11 to 60 V. The power supply of the module has a built-in protection circuit for inverse connection of the supply voltage and circuits that prevent passage of transitions.

The module has an excellent stability in time and does not require calibration or any maintenance. In the front of the module, below the front label, there are two multi-port trimmers for precise adjustment of the offset and gain. Both values are set before delivery and the user can overbalance these values according to their needs in the range of ± 3 to ± 10. The CB-30 family of transmitters can be mixed within the same application with other families of isolation modules. They can be plugged into the measuring system and disconnected from it without turning off the power of the system or shutting down the system

Power supply for transmitters

For power supply up to 50 transmitters, the CS-PS-48, 48W power supply (left-hand) is recommended, while the power supply of a number of conditioners should use a CS-24-90 of 90W source, which can, under full load, power up to three times more transmitters, although such a large number of transmitters are recommended to be powered from multiple el. sources. Transmitters do not support the rail T-BUS connector because they are powered through a loop.

The CS-PS-48 source operates in a wide voltage range from 85V to 265V AC. Both power sources operate in a wide voltage range from 160V to 265V AC. If the user does not want to use this type of power, it can also use other electrical sources.

The PCB of conditioner can be protected, on request, with special lacquer that protects electronic components from moisture, corrosion and other types of contamination, which can significantly extend the life of this product and in terms of long-term measurement accuracy. This conditioned conditioner can be applied in many aggressive environments. For example: on ships or on the seashore, in conditions of aggressive vapors, acid, water and other places with high humidity, etc.

Picture to the left: Power supply for CS-24-30 transmitters

Specifications and characteristics

(tipically at 25°C)

Parameter	CB-30 milliVolt input	CB-30 Volt input
Standard bipolar bands	±5 mV to ±500 mV	±1 V to ±20 V
Standard unipolar bands	0 to 10 mV and 0 to 500 mV	0 to 1 V and 0 to 1000 V
Input Bias current	±0.5 nA	±0.05 nA
Input resistance	50 MΩ	3 MΩ
Continuous input protection max.	250 Vrms	250 Vrms for range up to 200 V
RL for 24 V supply	650 Ω	650 Ω
NMR (50 Hz)	80 dB	80 dB
Transients	ANSI/IEEE C37.90.1- 1989	ANSI/IEEE C37.90.1- 1989
CMV, In-Out, In-Power	Continuous 1500 V	Continuous 1500 V
CMR 50Hz	160 dB	160 dB
Accuracy 25 ° C	±0.03% of range	±0.03% of range
Non linearity	±0.01% of range	±0.01% of range
Subsequent adjustment	±10% offset and gain minimum	±10% offset and gain minimum
Stability of offset	±25 ppm/°C	±25 ppm/°C
Stability of reinforcement	±75 ppm/°C	±75 ppm/°C
Output noise 100 KHz	3 µArms	2 µArms
Frequency bandwidth -3 dB	3 Hz (Options: 3 KHz and 10 KHz)	3 Hz (Options: 3 KHz and 10 KHz)
Response Time, Span 90%	170 ms	170 ms
Output range	4 to 20 mA	4 to 20 mA
NMR (50 Hz)	80 dB	80 dB
Power supply	From 11 V to 60 V	From 11 V to 60 V
Power consumption	3 mA to 30 mA max.	3 mA to 30 mA max.
Temperature range (ambient)	-40 to 80 °C	-40 to 80 °C
Working range	-40 to 85 °C	-40 to 85 °C
Storage	-40 to 85 °C	-40 to 85 °C
Relative Humidity	Without condensation 0 to 95%	Without condensation 0 to 95%
Installation DIN EN50022	35 x 7,5 or 35 x 15	35 x 7,5 or 35 x 15
Dimensions of the conditioner mm	L:114 x W:22,5 x H:105	L: x W:22,5 x H:105

Prices and specifications can be changed

Prices and types

milliVolt transmitters
Table 1.

Label	Input voltage	Output	Price € 1-49	Price € 50-249	Price € 250+
CB-30-00	±5 mV	4 to 20 mA	90	79	69
CB-30-01	±10 mV	4 to 20 mA	85	75	65
CB-30-02	±50 mV	4 to 20 mA	79	65	55
CB-30-03	±100 mV	4 to 20 mA	79	65	55
CB-30-04	±200 mV	4 to 20 mA	79	65	55
CB-30-05	±500 mV	4 to 20 mA	79	65	55
CB-30-06	0 to 10 mV	4 to 20 mA	79	65	55
CB-30-07	0 to 50 mV	4 to 20 mA	79	65	55
CB-30-08	0 to 100 mV	4 to 20 mA	79	65	55
CB-30-09	0 to 200 mV	4 to 20 mA	79	65	55
CB-30-10	0 to 500 mV	4 to 20 mA	79	65	55

Volt transmitters
Table 2.

Label	Input voltage	Output	Price € 1-49	Price € 50-249	Price € 250+
CB-30-11	±1 V	4 to 20 mA	79	65	55
CB-30-12	±5 V	4 to 20 mA	79	65	55
CB-30-13	±10 V	4 to 20 mA	79	65	55
CB-30-14	±20 V	4 to 20 mA	79	65	55
CB-30-15	0 to 1 V	4 to 20 mA	79	65	55
CB-30-16	0 to 5 V	4 to 20 mA	79	65	55
CB-30-17	0 to 10 V	4 to 20 mA	79	65	55
CB-30-18	0 to 20 V	4 to 20 mA	79	65	55
CB-30-19	0 to 100 V	4 to 20 mA	79	65	55
CB-30-20	0 to 200 V	4 to 20 mA	79	65	55
CB-30-21	0 to 300 V	4 to 20 mA	89	75	65
CB-30-22	0 to 400 V	4 to 20 mA	89	75	65
CB-30-23	0 to 500 V	4 to 20 mA	89	75	65
CB-30-24	0 to 600 V	4 to 20 mA	95	80	70
CB-30-25	0 to 1000 V	4 to 20 mA	99	85	75

Prices are without VAT

Option 1. Transmitters typically have a frequency band of 3 Hz. For a bandwidth of 1 kHz or 10 kHz (-3 dB), the price is 3 € higher.

Option 2. Commodity-protected transmitters for high-humidity environments have a 10 € higher price.

Option 3. Transmitters artificially tested with the Burn-in process, 48 hours at 60°C have a 15 € higher price.

Option 4. Transmitters by special user specification: the first piece is 150 €.

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