Warbling Alarm Circuit

The Warbling Alarm is made up of sawtooth wave generator and voltage controlled tone generator operated in tandem. Q1, R1, R2, C1, R3 comprise the sawtooth wave generator.

At the instant power is applied to the circuit, the voltage across C1 and hence at the anode of Q1 would be zero. C1 would then be slowly charged by R3 towards +12V. Once the voltage across C1 exceeds the value of the voltage appearing on the gate of Q1 as set by R1 and R2, the PUT (Programmable Unijunction Transistor) fires, that is, it will conduct, causing C1 to quickly discharge.Once C1 is discharged, Q1 will turn OFF, causing another charge - discharge cycle to be initiated. The manner in which the voltage across C1 varies, when plotted against time, resembles a sawtooth, hence the name sawtooth wave.

Inserting Alarm System to an Oil Pump Control Circuit

At some point in time, you may happen to have an old industrial pump unit wired inside an existing control panel that would require circuit modification in order to include an alarm system. What is being referred to here are pump systems most commonly found in industrial facilities such as oil pump, hydraulic pump, grease pump, water pump, air pump or air compressors, but nevertheless, the electrical circuit presented in this article may also be used to set an example to provide idea for other similar applications.

In heavy industrial facilities, one of the important foundation of a good working machinery is dependent on the condition of a well-oiled mechanism. This pertains to having a reliable lubrication system that ensures all moving parts of every machinery in the factory are well-lubricated in order to diminish friction and grinding on the machine's mechanical joints and contacts.

Electrical Circuit for Controlling a Lifting Electromagnet for Overhead Cranes with Top Running Trolley Hoist

When the need to conveniently pick up and lift heavy iron or steel objects for transferring from one place to another was seen as a necessity in heavy industrial facilities, the concept of using an electromagnet was implemented due to its ability to be turned ON and OFF which was then incorporated effectively to the hoist function of overhead cranes.

Overhead-travelling-crane magnets are electromagnetic device attached to the crane's hook to magnetically pick up heavy metallic loads for hoisting and transferring.  Cranes that are fitted with a lifting magnet are equipped with an electromagnet control circuit.

Wiring Connection for a Three Wire Solid State DC Proximity Sensor Without PLC

The previous article illustrated the concept of the wiring connection of a 3 wire DC proximity sensor to a PLC (Programmable Logic Controller). Alternatively, in this article, I will explain another approach on the wiring connection of the same proximity sensor but without using a PLC.

How to Connect a 3 Wire DC Solid State Proximity Sensor to a PLC

Knowing how to connect a 3 wire DC solid state proximity sensor to a PLC (Programmable Logic Controller) is dependent on the type of proximity sensor and the PLC to be used that is specific to the design of the circuit and the preferred application.

Pinch Roller Automatic Grip Control After Shear Cut Using PLC Program

What is a pinch roller? A pinch roller is a rotating machine consisting mainly of two rollers arranged in parallel either horizontally or vertically depending on the process required to pull the material that is rolled in the mill. These two rollers are coupled to a variable speed electric motor which is constantly rotating at a preset speed that is synchronized with the speed of the preceding finishing roller located before the pinch roller.

Electrical Wiring Diagram Forward Reverse Motor Control and Power Circuit Using Mitsubishi PLC

This blog post is not only intended to provide a graphical illustration but will also explain the procedure and the operational concept involving the wiring principle of the forward reverse motor control circuit with the use of a PLC (Programmable Logic Controller).

A diagram of the ladder program contained inside the PLC memory specifically for this function is also included below to clearly illustrate the operational sequence for command execution of this motor control system.

Electrical Wiring Diagram Star Delta Control and Power Circuit Using Mitsubishi PLC Program

This article is intended to diagrammatically demonstrate the concept of the wiring principle of a star delta (wye delta) motor control and power circuit when using a PLC (Programmable Logic Controller) ladder program to control the switching of a 440 volts induction motor.

Motor Start Stop Time Sequence Electrical Control Circuit Using PLC Ladder Program

The following is a sample tutorial of a typical timing sequence involving a start and stop function of a common DOL (Direct On Line) motor control circuit using PLC (Programmable Logic Controller) ladder program.