Project Files of Electric Bell Library for Proteus V1.0 (Arduino + 12V Trembler Bell)

ELECTRIC BELL LIBRARY FOR PROTEUS - V1.0 (a 12 V DC trembler bell: two coils, an
interrupter contact, a hammer and a gong)
Designed by The Engineering Projects
www.TheEngineeringProjects.com

IMPORTANT LINKS
Article (read it first - pictures, step by step, every feature explained):
  https://www.theengineeringprojects.com/2026/11/electric-bell-library-for-proteus-v1-0.html
Report a bug or suggest a feature (our forum):
  https://www.theengineeringprojects.com/forum/category/motor-driver-proteus-library
The demo runs on our Arduino UNO V4.0 (included) - working LEDs, RESET and a
built-in serial monitor - its own article:
  https://www.theengineeringprojects.com/2026/10/arduino-uno-library-for-proteus-v40.html
The demo's driver is our L9110S Motor Driver - a SEPARATE library, not in this
package: download and install it first - its own article:
  https://www.theengineeringprojects.com/2026/10/l9110s-motor-driver-library-for-proteus-v1-0.html
Support us (the libraries are free):
  https://www.theengineeringprojects.com/donate

FILE STRUCTURE
Electric-Bell-TEP-v1.0/
|-- Proteus Library Files/
|   |-- ArduinoV4TEP.LIB                              201.9 KB   TEP Arduino boards V4.0 (UNO) -> LIBRARY
|   |-- TEPBELL.LIB                                    17.3 KB   the library -> LIBRARY folder
|-- Proteus Model Files/
|   |-- TEPARDUINO.DLL                                883.5 KB   the Arduino board model -> MODELS folder
|   |-- TEPBELL.DLL                                   273.5 KB   the model -> MODELS folder
|-- Proteus Simulation/
|   |-- Bell_Demo.hex                                  21.1 KB   the demo firmware
|   |-- Electric-Bell-L9110S-ArduinoUnoV4.pdsprj       23.2 KB   the demo project
|   |-- TEPARDUINO.DLL                                883.5 KB   copy of the board model
|   |-- TEPBELL.DLL                                   273.5 KB   copy of the model
|-- Arduino Code/
|   |-- Bell_Demo/Bell_Demo.ino                         4.3 KB   the demo sketch (source of the .hex)
|-- README.txt                                        ~16.9 KB   this file
Total: 2.54 MB (unzipped). The C++ source code of the models is not included.

WHAT IS IT?
A simulation model of the electric trembler bell - the bell of school corridors,
factory shifts, fire alarms and old doorbells. It needs no electronics: two
coils on a yoke pull an iron armature that carries the hammer, and a contact in
series with the coils, inside the bell, breaks the circuit as the armature moves
in. The spring throws the armature back - the hammer strikes the gong on the way
in - the contact closes again, and it all repeats twenty-odd times a second. So
steady DC on its two terminals makes it ring. Our own model:
  * The coils between + and - are in the circuit while the contact is closed,
    with their resistance and an inductance that grows as the armature closes:
    24 ohm (25 C), 36 mH open, 103 mH at the pole - a 12 V, 0.5 A bell. While
    the contact is open the terminals carry nothing; the coils' current dies
    inside the bell (the contact's spark and its suppressor).
  * The armature is pulled by the coils' current against its spring: it moves
    from 316 mA (7.6 V on a 12 V bell). The contact opens below a 0.9 mm gap
    and closes again above 1.5 mm; the hammer meets the gong at 0.4 mm.
  * At 12 V it rings at about 26 strikes a second with 0.47 A peaks; it still
    rings at 9 V (17 a second) and 8.5 V (14), and below about 8 V the hammer
    never moves: TOO WEAK.
  * A PWM drive averages down: at 50 % (6 V on average) it never strikes; the
    watch sees the PWM and says so.
  * More current than the coils are rated for (a 12 V bell on 24 V) gives a
    warning; a long ring warms the coils (a 6 W coil for short rings).
  * The watch: RINGING (strikes a second, the voltage), STOPPED (how long it
    rang, how many strikes), NO STRIKE (the contact chops but the hammer stops
    short), TOO WEAK, a PWM drive, too much current, hot coils.
The symbol shows the bell lid-off from the front: the dark base, the red gong,
the two copper coil bobbins on their steel yoke, the armature with its hinge
spring and contact screw, the hammer by the gong's rim and the two brass screw
terminals with the red + and black - wires. At Run the hammer swings and the
gong shows faint rings while it rings. The plate, the COIL LED (green while
current flows - held 0.15 s so the trembler's pulses show as a steady light),
the rating line and the strip under the plate (STRIKES, RATE, CURRENT, OPEN
PANEL) are TEP additions; the real bell has none of them.

ONE DEVICE (search "bell" in Pick Devices):
  ELECBELLTEP    "Electric Bell V1.0"   (category Electromechanical > Motors),
                 model TEPBELL.DLL
  The pop-up panel "TEP Electric Bell" opens at Run (and with OPEN PANEL on the
  strip) - the look of the TEP Serial Monitor. Tabs Bell, Graphs, Event log and
  Check; gear and ? icons for Settings and Help; the palette icon switches the
  theme:
    Bell       the state in big letters (RINGING - 25.7 STRIKES A SECOND, 0.47
               A PEAK; TOO WEAK; NO STRIKE; SILENT); the gong and the hammer,
               the contact; the live values (strikes a second, strikes, ring
               time, peak current, the voltage while driven, the contact, the
               hammer, the coils); the last quarter second: the current, the
               hammer and the contact - the trembler's chopping.
    Graphs     the strike rate, the current (20 ms averages) and the coils'
               temperature over the last 10, 30 or 60 s. Live / Freeze.
    Event log  RINGING ("RINGING - 25.7 strikes a second at 11.3 V across the
               bell"), STOPPED ("STOPPED - rang 0.93 s, 25 strikes (25.7 a
               second)"), TOO WEAK, NO STRIKE, a PWM drive, the warnings;
               filters All / Rings / Warnings, Pause, Clear
    Check      Good for: a bell that stays silent, only buzzes, rings weakly or
               gets hot - the supply, the strike, the rate, the current, the
               contact, the drive, the coils, with tips
    Settings   theme, text size, open at Run, window size
    Help       report a bug, suggest a feature, article, updates, donate,
               forum; Copy diagnostics for a bug report

TEST STATUS
V1.0: verified in Proteus 8.5 on 29 Oct 2026 (the demo project as shipped: an
A3 sheet, an Arduino UNO V4.0 with its built-in monitor, our L9110S driver -
its pop-up version, from its own library - on +12V, RV1 and the bell; all
pop-ups open). What the runs showed:
  * The project loads and starts cleanly; one ring at power-up, RV1's length
    (30 %: 0.97 s): "RINGING - 25.7 strikes a second at 11.3 V across the
    bell", 453 mA, "STOPPED - rang 0.93 s, 25 strikes (25.7 a second)"; the
    COIL LED lit, the gong ringing on the sheet.
  * "door": two short rings - "STOPPED - rang 0.12 s, 4 strikes" twice.
  * "school": three rings of 1 s - 25.7, 25.6 and 25.6 strikes a second, 26
    strikes each.
  * "pwm 50": "a PWM drive (about 974 Hz): a trembler bell wants steady DC -
    its hammer weakens", then "TOO WEAK - 219 mA through the coils, under the
    316 mA pull-in: the hammer never moves" - 6.0 V across the bell on
    average; the Check page: the supply and the strike in red.
  * "alarm" then "stop": "RINGING - 25.5 strikes a second", "STOPPED - rang
    2.56 s, 66 strikes (25.4 a second)" - 177 strikes in the run, the coils
    at 29 C.
  * The L9110S's own pop-up: motor A switching the bell on and off.
  Plus automatic checks on a PC, 0 failed: 13 on the bell (12 V: 26.0 strikes
  a second, 0.48 A peaks, pull-in 316 mA (7.6 V), 36 / 103 mH; it rings down
  to 8.5 V and is too weak at 6 V; 24 V on a 12 V bell: 0.93 A and the
  warning, a 24 V bell rings on 24 V; a 50 % PWM never strikes and its
  frequency is read, 85 % still rings; a ding-dong is two rings; three school
  rings each logged at the true rate; a 60 s ring warms the coils to 50 C;
  the driven voltage is kept after a ring and a 50 % PWM gives about 6 V;
  every event text fits); 2 on the pop-up pages rendered; the demo project
  read back from disk (57 checks: devices, pins, wires, labels, no wire through
  a part, no crossing).

INSTALLATION (about 2 minutes)
1. Close Proteus. Extract the WHOLE ZIP to a normal folder (e.g. Desktop).
2. Copy everything in "Proteus Library Files" (TEPBELL.LIB and our Arduino
   library V4.0, ArduinoV4TEP.LIB) to the LIBRARY folder of Proteus, for
   example:
     C:\Program Files (x86)\Labcenter Electronics\Proteus 8 Professional\LIBRARY
   (on some PCs: C:\ProgramData\Labcenter Electronics\Proteus 8 Professional\
   LIBRARY - use the folder that already holds Proteus's own .LIB files).
3. Copy TEPBELL.DLL and TEPARDUINO.DLL from "Proteus Model Files" to the MODELS
   folder (...\Proteus 8 Professional\MODELS). The demo's driver is NOT in this
   package: install our L9110S Motor Driver library the same way (its own ZIP -
   see IMPORTANT LINKS): TEPL9110S.LIB and TEPL9110S.DLL.
4. Delete TEPBELL.IDX from the LIBRARY folder if it is there.
5. Start Proteus. In Pick Devices (P) search "bell".

RUN THE DEMO
"Proteus Simulation\Electric-Bell-L9110S-ArduinoUnoV4.pdsprj" - keep the .hex
file and the DLLs beside the project (with the L9110S library installed).
  ARD1: Arduino UNO V4.0 running Bell_Demo.hex, its serial monitor built in
        (window "TEP Arduino UNO - ARD1").
  DRV1: our L9110S driver (pop-up version, a separate library): A-IA on D5,
        A-IB on D6, VCC on +12V, GND - by net labels.
  BL1:  the bell: + on the L9110S's A-OA, - on A-OB (motor A) - straight wires.
  RV1:  10k pot on A0 (the length of a plain "ring", 0.1 - 3 s).
  1. Press Run. The monitor and the two pop-ups open (move them aside). The bell
     rings once, RV1's length.
  2. Type in the monitor and press Send: ring 2, door, school, alarm, stop,
     pwm 50.
  3. Double-click BL1: VOLTAGE (6 / 12 / 24).
  4. The pop-up: Bell, Graphs, Event log, Check.

WIRING (the same idea on a real bell)
  L9110S          Arduino UNO / supply
   A-IA, A-IB     D5, D6
   VCC            12 V (the L9110S takes 2.5 - 12 V; its inputs stay 5 V
                  logic), GND to the UNO's GND
  Bell            L9110S
   +  /  -        A-OA / A-OB
In the sketch (no library needed): the bell ON for the length of the ring, then
OFF - never a PWM:
  digitalWrite(BELL_A, HIGH); digitalWrite(BELL_B, LOW); delay(1000);   // ring
  digitalWrite(BELL_A, LOW);                                            // off (brake)
The demo does the same with millis(), so the monitor and RV1 keep working.
REAL HARDWARE:
 * A 12 V trembler bell takes 0.3 - 0.5 A: an NPN transistor or a logic MOSFET
   with a diode across the bell, a relay, or an H-bridge - never a pin.
 * Give it steady DC for the ring: its own contact does the chopping. A PWM
   (or a supply too low) makes the hammer stop short or never move.
 * Its contact sparks as it opens; a 100 nF capacitor across the contact
   (inside the bell) makes it last. The adjusting screw sets the gap: too far
   and it only buzzes, too close and it never opens.
 * Ring it in short bursts: the coils are made for seconds, not minutes.

THE DEMO SKETCH ON THE SERIAL MONITOR (Bell_Demo V1.0, 9600 baud)
  ring       one ring, RV1's length          ring 2     one ring of 2 s
  door       ding-dong: two short rings       school     three rings of 1 s
  alarm      ring until stop                  stop       silence
  pwm 50     one ring of 1 s at a 50 % PWM (a trembler bell wants steady DC)
  help       the list
EXPECTED MONITOR OUTPUT
  Electric Bell demo - The Engineering Projects
  L9110S on 12 V: the bell on motor A (D5 / D6). Steady DC rings it; RV1 sets the ring.
  Commands: ring | ring 2 | door | school | alarm | stop | pwm 50 | help
  Ring - 0.97 s
  Done

PROPERTIES (double-click the part > Edit Properties)
  VOLTAGE    the bell's rating: 6 (6 ohm, 1 A), 12 (24 ohm, 0.5 A) or 24 (96
             ohm, 0.25 A); default 12
Every run starts again from the properties.

TROUBLESHOOTING
* It stays silent and nothing is logged: no current - the L9110S has no 12 V,
  or its inputs are not driven.
* "TOO WEAK": the supply is too low for the bell (a 24 V bell on 12 V), or a
  PWM averages it down - give it its rated voltage, steady.
* "NO STRIKE": the contact chops but the hammer stops short of the gong - more
  voltage, steady DC.
* It rings fast and hot, "coil current ... x the rated": a 12 V bell on 24 V.
* The part is not simulated: TEPBELL.DLL is missing from MODELS and from the
  project folder. No driver: install our L9110S library (TEPL9110S.LIB /
  .DLL). No UNO / no monitor window: TEPARDUINO.DLL, or click the UNO's USB
  port.
* The pop-up does not appear: click OPEN PANEL on the strip, or turn "Open the
  panel at Run" on its Settings page back on.

BUG REPORTS AND FEATURE REQUESTS
Please post them in our forum with a screenshot, the Serial Monitor text, the
simulation log and the pop-up's Copy diagnostics text:
  https://www.theengineeringprojects.com/forum/category/motor-driver-proteus-library

SUPPORT US
This library is free. If it saves you time, please support our work:
  https://www.theengineeringprojects.com/donate

LICENCES AND THIRD-PARTY NOTES
* The bell model (TEPBELL.DLL), the symbol and artwork and the Arduino Library
  V4.0 (ArduinoV4TEP.LIB / TEPARDUINO.DLL) are made by The Engineering
  Projects. The model is an independent implementation written from the
  typical data of 12 V DC trembler bells. The models use only standard Windows
  libraries; no Visual C++ redistributable is needed.
  The C++ source code is not included. The demo's driver, our L9110S Motor
  Driver library (TEPL9110S.LIB / TEPL9110S.DLL), is a separate download.
* The demo's .hex is built from the demo sketch and the Arduino AVR core 1.8.6,
  which includes LGPL-licensed code; its source code is available at
  https://github.com/arduino/ArduinoCore-avr/tree/1.8.6
* Proteus is a product of Labcenter Electronics and is not included. Arduino is
  a trademark of Arduino SA. This library is not made or endorsed by any bell
  maker, Arduino or Labcenter.

REBUILDING THE FIRMWARE (OPTIONAL)
The HEX file is supplied; Arduino IDE is not needed to run the demo. To edit
the sketch, open Arduino Code\Bell_Demo\Bell_Demo.ino, select Arduino Uno and
use Sketch > Export Compiled Binary. The sketch needs 7,656 bytes of flash
(23 % of the UNO) and 311 bytes of RAM.

MODEL SCOPE AND LIMITS
Modelled: the coils (resistance with its temperature, an inductance that grows
as the armature closes), the interrupter contact in series (opening and closing
with the armature), the armature's pull against its spring, the hammer and the
gong (the strike, the bounce, the ring dying away), the coils' heating, the
watch's states and warnings.
How it runs: while the contact is closed the coils are in the circuit as a
flux-linkage companion over the analog step (a conductance and a source that
follow the armature); while it is open only a tiny leak; the armature, the
contact and the coils' internal current run in 10 us sub-steps between the
analog points, which are held to 50 us while the bell is driven or moving (2 ms
at rest).
Not modelled: the sound itself, AC operation, the wear of the contact, a
single-stroke or a motor-driven bell.

VERSION
TEP Electric Bell library V1.0 (Oct 2026). Device ELECBELLTEP (TEPBELL.LIB /
TEPBELL.DLL). Demo sketch Bell_Demo V1.0. Demo driver: L9110SADVTEP (TEP L9110S
Motor Driver library V1.0, a separate library). Demo board: ARDUINO UNO V4.0
(TEP Arduino Library V4.0) with its built-in serial monitor.