Voltage measurement box#

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Fig. 280 Voltage measurement PCB#

Source#

General description#

This PCB is designed to measure voltages up to 60V or 1000V on four channels, depending on the configuration of the voltage dividers. The supply can be taken from the voltage interface connector of an Analog LTC2311-16 board (24V). Alternatively, an external power supply with a voltage range of 7V to 65V can be used. The measurement signals are reduced to a level of +-5V and low-pass filtered. The measurement signals from all four channels are routed to an Ethernet connector and can be connected to an ADC channel of Analog LTC2311-16.

Layout#

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Fig. 281 Functional areas of the voltage measurement box (top side)#

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Fig. 282 Functional areas of the voltage measurement box (bottom side)#

The PCB is structured in functional areas as shown in Fig. 281 and Fig. 282.

  1. 4mm jack connectors for voltage measurement. V+ and V- for each channel.

  2. Ethernet connector to the ADC adapter card Analog LTC2311-16.

  3. Isolation of measurement signal and signal adaptation to +/- 5V and low-pass filtering.

  4. Power supply with 7V to 65V input range. Either use connectors J1, J2 (IPL1-102-02-L-D-K, Cable: MMSD-02-xx-x-xx.xx-x-x) or J4 (TSW-102-07-F-S).

  5. Voltage dividers for up to 1000V measurement range.

Power supply#

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Fig. 283 Pins for VIN are marked in blue and GND in orange. Connectors are marked in yellow. Cable should be configured accordingly.#

The PCB can be powered in two ways:

  1. J1,J2: VIN/GND from the Analog LTC2311-16 card with a manufactured power supply cable (Type MMSD-02-xx-x-xx.xx-x-x to MMSD-08-xx-x-xx.xx-x-x). Alternatively to external power source.

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Fig. 284 Connector on the LTC2311_16 card for power supply to the voltage measurement box.#

Note

Use pins 2 and 10 as return ground!
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Fig. 285 Physical pins on the Analog LTC2311-16 card.#

  1. J4: Connect external power supply to pins.

Pinout#

The pairs of the RJ45 Ethernet connector map to the voltage measurement channels as follows:

Connected

Pin on RJ45 (RJ45-Belegung)

ADC

Channel

\(V_\mathrm{in,p}\)

\(V_\mathrm{in,n}\)

ADC 1

1

7

8

ADC 2

2

4

5

ADC 3

3

3

6

ADC 4

4

1

2

Variants#

The PCB can be ordered in two variants:

  • 60V Version with 2x 150k and 3x 0R resistors per voltage divider leg

    • measurement gain in DB: -23.67 dB

    • cutoff frequency: 2kHz

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Fig. 286 Verification of gain and cutoff frequency for 60V version#

  • 1000V Version with 5x 1M resistors per voltage divider leg

    • measurement gain in DB: -48.98 dB

Assembly and Connection#

A 3D-printable housing is available for the voltage measurement PCB. The assembly with all necessary parts, including a bill of materials (BOM), is shown below. The PCB can be used without the housing, but the setup is more rugged and clean with the housing.

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Fig. 287 Assembly drawing of the voltage measurement box#

Table 89 BOM for voltage_measurement_box assembly#

No

Description

Manufacturer Part Number

Amount

Hint

1

Housing body

housing_body.stl

1

Print on any FDM printer with PLA material

Housing cover

housing_cover.stl

1

Print on any FDM printer with PLA material

2

PCB

uz_per_voltage_measurement_box

1

Choose variant with proper voltage rating

3

Socket head cap screw

EN ISO 4762 M3x8

8

4

Würth Steel spacer stud M3x28

970280321

4

Downloads#

Designer#

Designed by Eyke Aufderheide (TU München), 07/2025