- Build Your Inspiring 240VAC Mains Smoke Detector Alarm Circuit
- Build a Powerful 200mA Security Siren Circuit
- 3V Mini Alarm Circuit Diagram & Build Guide
- Laptop Alarm Circuit: Build Your Theft Protection Scheme
- DIY Motion-Activated Alarm Circuit with 100W Lamp
- 5-Digit Alarm Keypad: Build Your Secure Circuit Diagram
- Build Your 4-Digit Alarm Keypad Circuit Diagram
- Build Your 20-Minute Battery Burglar Alarm Schematic
- Enhanced Shed Alarm Circuit Diagram with 30-Second Delays
- Simple Fire Door Alarm Circuit Design & Timing Control
- Simple Shop Alarm: Build a 3-5 Second Beep Timer
- Four Transistor Alarm Circuits: Design & Build Your Own!
- 12 Small CMOS Alarm Circuits Diagrams – Build Your Own!
- Build Your 12V Burglar Alarm Circuit Diagram
- Build Your 30-Second Alarm: Circuit Diagram & Design
12 Small CMOS Alarm Circuits Diagrams – Build Your Own!
Description
This collection presents a selection of compact, self-contained alert circuits. The primary details concerning each alarm circuit are outlined on the corresponding circuit diagram. All of these circuits exhibit a remarkably low standby current, making them exceptionally well-suited for operation powered by batteries. Each pair of circuits is printed onto an A4 sheet. Although categorized as alarm circuits, these circuits possess diverse potential applications.
Sw1 is depicted as either a micro-switch or a magnetic-reed contact – provided it fulfills the required function; utilizing whichever switch type is most appropriate for your specific application is permissible. The incorporation of multiple switches is encouraged if it enhances the design. The output device, a “piezo” buzzer, necessitates a current of approximately 10mA. However, substitution with a relay is possible; the relay contacts can then be employed to control any desired device. It is crucial to ensure that the relay coil doesn’t draw more than approximately 50mA, otherwise the transistor may be subjected to overload.
Schematic Diagrams 1 & 2
Schematic Diagrams 3 & 4
Schematic Diagrams 5 & 6
Schematic Diagrams 7 & 8
Schematic Diagrams 9 & 10
Schematic Diagrams 11 & 12
The Cmos 4093 represents the Schmidt-Trigger variant of the Cmos 4011. For the purposes of this documentation, these two components can be used interchangeably. However, the 4093 demonstrates enhanced switching performance, which becomes particularly noticeable during prolonged time periods.
The exact duration of any time interval will vary based on the properties of the individual components utilized, particularly the tolerance of the capacitors and the precise switching points of the Cmos Gates. These factors directly influence the circuit’s behavior and performance.
In the context of circuits 11 & 12, the values of R6 and R7 should be considered as a rough guideline. The switching point of Gate 3 and the characteristics of the thermistor will ultimately determine the actual temperature range accessible. Modifying the value of R6 will allow access to distinct sections of the temperature scale, while adjusting the value of R7 will enable alteration of the adjustment width available.