Signs with e-paper – ELP 191

A new type of stop signs which integrates LCD type e-paper K813.3 that is integrated as per customer requirements (there is a PID sign in the picture). The sign is powered by ca. 60 x 60 cm solar panels, and on sunny days energy is stored in a suitable lithium accumulator. The sign is connected to a control server via LTE, and it has a command receiver and  a “night“ light button.

Basic properties of e-paper stop panel

• Departure panel is integrated in the stop sign as per customer requirements.
• Planed panel lifespan is at least 10 years (for now based on component choice).
• Individual component placement provides easy service or replacement – given by sign construction.
• Cover glass of the display devices is antivandal and anti-reflective.
• Operation temperature: -10 up to +60 °C (in 2020 there was -10 °C improvement in comparison with temperature tests  of e-paper from  2018).
• Device components:
  • new special low input power control unit CSU 60 (our own development),
  • display e-paper, size 13,3″
  • data modem GSM/LTE (WiFi is not recommended due to high consumption)
  • solar power system – the panel size is  60×60 cm to make it proportional to the size of the sign
  • command receiver for the vision impaired, a new version of selective reception and consumption - EPNEV 1,24,
  • speaker with amplifier for requested announcements,
  • antennas (GSM modem, command receiver).

Power supply

In the economical version with solar panels the basic consumption of the whole sign is 50 – 70 mW.  Signs can be powered as follows:

• Continuous power supply from a source.
• Night power supply from public lightning (power supply form accumulators during the day). In this case the battery capacity has to run 6 hours charging / 18 hours discharging (long summer day).
• The accumulator can be charged by a solar panel – in this case sufficient battery capacity (operation for at least 60 days without charging) and sufficient solar panel performance are ensured. A new control system of lithium accumulators – BMS  was designed for this purpose (can be supplied independently).

Display on e-paper

• The display is prepared as per system operator requirements – the attached picture shows 4 displayed lines (can be chosen) – see. e-paper management.
• U e-paper  displays single-color text – 16 shades of gray.
• At low visibility, active illumination can be used. It is activated by a request button (a capacity button is used in a way to avoid the necessity of using antivandal). This button can only be used from dusk till dawn – it is controlled by a light sensor.

Error states

If the device is out of order (critically low battery charge, data connection interruption, hardware malfunction, etc.) it automatically switches to the „fail-safe“ mode. The device does not display information older than 2 minutes. The display either shows a text (e.g. panel out of order) or the e-paper is completely deleted (the active part of the display is deleted).

Information for the vision impaired

The panel behaves in a standard way – it reads the contents of the display out loud at a command. A new type of command receiver was developed – low input power EPNEV 1.24.

Supervision

Signs can be supplied with a supervision system (server) for controlling and supervising them. Thanks to this system you can:

• monitor the state of individual components of the sign – e.g. battery charge (if used), temperature, the state of the solar panel, etc.
• use state diagnostics included in the supervision SW – in operation, connection failed, and other error messages.
• see the content of the panel.
• other possibilities  (e.g. remote restart of the device).

Data source

The device displays information from the required system as agreed with the sign operator. A support server has to be used that converts the data from the outside server to the company protocol for communication with signs. The support server is used to save energy in signs (it may not be necessary for signs with permanent power supply)

Pic. no.2: ELP 191 at night – without illumination compared with passenger activated LED illumination.