1 Minute to 2 Hour Timer Using IC 4060

Free circuit dot com presents the timer circuit with IC 4060 as this circuit is simple to make the project or devices.

This timer circuit can  set time at 1 minute to 2 hours.

Frist information, Technically, the IC 4060 is a 14-stage ripple carry binary counter, the oscillator and divider of a monolithic integrated circuit, contained in a 16-pin dual-in-line housing with ceramic or plastic. A phase of the integrated oscillator is a key feature of the integrated circuit, which keeps the number of components in the integrated circuit to a minimum at the design frequency generators or oscillators. The phase of the internal oscillator operation easily through a network of resistors and a capacitor connected to the pins #8, #9 and #10.

1 Minute to 2 Hour Timer Circuit Diagram

The timer time is determined by P1 and C1, through the following formula (seconds): t = 2.3 * (P1 + 18k) * C1 * 2 ^ 13 .

The basic structure of the IC can be understood from the following:

According to the rules of standard CMOS ICs, all entries are first captured by assigning them to specific business logic or simply a voltage (not exceeding the level of supply voltage). For integrated circuit pin # 9, 10, 11 and 12 are active inputs.  Resistance to pin No. 11 can be considered a type of terminal or the reference resistance value that ideally should be 10 times more than the resistor connected to the pin 10 (the combined value of the resistor and pot fixed series).

The capacitor connected to pin # 9 is, in general, non-polar type.

No Pin 12 is the reset input of the IC on the ground must be connected so that the IC function (swing). This entry positive stop immediately IC to oscillate and return it to its original state. Set the pen is connected to the ground of the integrated circuit for counting (oscillate) for some time (for example, 1 minute), the connecting pin to the positive terminal and to immediately stop the count reset to zero.

The rest of the pin-out, the outputs of the IC that generate oscillations specific speeds. Costs are expressed in multiples of two for the entire chain pinouts as shown in the diagram. Pin # 3 indicates the lowest frequency, the highest or pulses at time intervals while the spindle 7 with the highest frequency or pulses having the lowest time intervals.

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Quartz Clock Timebase

Many electronic projects call for a timebase generator, accurate to a second or so. One way of producing this is with a microcontroller, quartz crystal and some software. But a far cheaper and simpler approach is to recycle an old analogue quartz clock. After investigating a number of clocks the author discovered that they all use the same drive method: a tiny solenoid coil is pulsed by a current that reverses direction once a second. In the module illustrated this coil is connected between pins Pulse1 and Pulse2. Most of the time both pins are ‘high’ at supply voltage but every second the clock electronics pull first one and then the other of the pins down to ground for about 25 ms.

Quartz Clock Timebase Circuit Diagram:

We need just five additional components to complete the circuit (see diagram). When either of the pulse pins is at ground potential, the corresponding PNP transistor conducts. Once a second a narrow pulse is produced, which is ideal for our own digital circuitry. The author himself uses one of these clock modules as timebase for a data logger with excel-lent results. Although the clock originally used a 1.5 V supply, this new arrangement works fine with a 3-V lithium batter y. After three months using the same battery there have been no problems whatsoever.

 

Author : Claus Torstrick - Copyright :Elektor

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Touch-Free Timer Switch Circuit

This type of infrared proximity circuit is widely used as an electric switch where physical contact is not desired for hygiene purpose. For example, we commonly see use of infrared proximity sensors on public drinking fountains and in public washrooms. The simple circuit presented here can be operated by moving your hand in front of it. This is achieved by detecting the infrared light reflected by your hand onto a receiver device.

Circuit diagram :

Fig. 1: Touch-Free Timer Switch Circuit Diagram

Fig. 1 shows the circuit of the touch-free timer switch. It has two sections: transmitter and receiver. The IR transmitter is built around timer LMC555 (IC1), which is wired as an astable multivibrator. The multivibrator produces 38kHz pulses (at low duty cycle) that drive an infrared LED (LED1). This frequency can be tuned using a 10-kilo-ohm preset (VR1). A 220-ohm series resistor (R3) ensures that the current consumption of the IR transmitter is not out of arrangement.

The receiver section is built around IR receiver module TSOP1738 (IRX1), timer LMC555 (IC2) and a few discrete components. The TSOP1738 is an integrated miniaturised receiver for infrared remote control systems. Everything required for IR signal processing, including the PIN diode and preamplifier, are assembled on a lead frame and the epoxy package is designed as an IR filter.

 

When a short IR burst is received by IRX1 (as you wave your hand in front of the switch), the demodulated pulses are fed to the trigger input (pin 2) of the second LMC555 (IC2). This, in turn, triggers the monostable wired around IC2 and its output pin 3 goes high for a period determined by the 2.2-mega-ohm potentiometer and capacitor C5. This turns off the standby indicator (LED1) and transistor T1 conducts to drive the 5V relay (RL1). LED1 enables you to locate the switch in the dark. AC mains supply to the load to be switched-on is routed through the pole and normally-opened contacts of RL1 as shown in the diagram. The circuit works off regulated 5V DC.

Fig. 2: Pin configurations of TSOP1738, IR LED and BC547

Fig. 2 shows the pin configurations of TSOP1738, IR LED1 and transistor BC547. Assemble the circuit on a general-purpose PCB and enclose in a small plastic cabinet. Fit IR LED1 with a reflecting hood at a recessed position on the front panel of the enclosure. The dome-shaped face of the TSOP1738 should stick out from the front panel. Fit the time-control potentiometer (VR2) in an appropriate position. Finally, fit the standby indicator LED1 inside a suitable LED holder such that it slightly protrudes from the front panel. To prevent unwanted reflection of the IR beam, the finished unit should be mounted such that it does not face a nearby wall.

 

Fig. 3: Suggested enclosure

Using high-precision linear potentiometer VR2 and capacitor C5 (100µF), the time length can be set from nearly 1 second to 120 seconds. Attach a small paper dial on the front panel of the enclosure and mark various positions of the control knob of VR2 as shown in Fig. 3. The accuracy of the timer depends mainly upon the quality (and value) of timing capacitor C5. In practice, most electrolytic capacitors are rated on the basis of minimum guaranteed value and the real value may be higher.

Author :T.K. Hareendran - Copyright: EFY

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Simple Timer for Very Long Periods

Simple mechanical timers, which you can buy for a couple of pounds in every home improvement centre, are suitable for switching something on and off one or more times per day. They can be used to control a wide variety of devices, such as  lamps inside or outside the house,lighting for bird cages and aquariums, sump pumps, battery chargers, etc.

 

If you need to control something over a longer period than the standard 24 hours, you can use two timers with the second one plugged  into the first one (see photos). To determine what you can do with this arrangement, you  first need to determine how often the load  needs to be switched. For example, if the  first timer has 48 tabs the shortest ‘on’ time  is 30 minutes in 24 hours. This means that the  second timer will run for 30 minutes every 24 hours, so the maximum duration of a full cycle is 48 days. A device such as a charger for diving torches can be connected to the second timer.

To prevent the ‘on’ time of the second timer from exceeding 24 hours, it is essential to keep the ‘on’ time of the second timer shorter than that of the first timer. If a maximum cycle time of 48 days is too short, you can also connect a third timer. With three timers, the maximum cycle time is 2304 days (one ‘on’ time in approximately 6.5 years).

As you can see from the photos, the second timer may interfere with the tabs of the first timer if they are plugged together with one on top of the other. This can be avoided by turning the second timer by 180 degrees relative to the first one.

Author : Dirk Visser  - Copyright : Elektor

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Low Cost Electronic Clock

This circuit can be used for the safety of precious and valuable items. The low-cost electronic lock is suitable for use in homes and banks for lockers etc.The circuit consists of three thumbwheel switches, three DIP switch sets (each having eight switches), three inverter ICs (7404), three quad-AND gate ICs (7408), one quad-NAND IC (7400), one timer IC (555), few diodes/transistors and other passive components.

Circuit diagram :

Low Cost Electronic Clock Circuit Diagram

The Dip switches are supposed to be hidden and the actual code to be set on the thumbwheel switches must match the Dip switch settings, which will result in enabling of all AND gates (G1 to G11). The high output of the last AND gate is used for energising relay RL1 via DPDT switch S1, which in turn results in energisation of solenoid coil from mains supply via its N/O contacts. This causes the steel rod of the solenoid to be pulled against the spring tension and the lock gets opened. If the code selected via thumbwheel switches does not match the DIP switch settings and DPDT switch S1 is put on, the low output of AND gate G11 will result in setting of latch formed by NAND gates N13 and N14 as well as sounding of buzzer through transistor T2 which gets forward biased. Resetting of buzzer as well as the latch is possible by momentary depression of switch S2. It is therefore desirable to install switch S2 also in a hidden place.

For proper operation of the circuit, switch S1 is initially kept in off position and desired code is selected with the help of the dip switches. This is followed by resetting of latch by momentary depression of switch S2. Now the system is ready for operation. Switch S1 is to be put on only after correct code is selected with the help of thumbwheel switches for opening of lock (for energisation of solenoid), else it will result in sounding of alarm (buzzer), as explained earlier. Diode D2 prevents the positive voltage present at pin 1 of NAND gate N13 (when switch S1 is off) from reaching transistor T1 base and energising relay RL1 and the solenoid. A lock using solenoid coil can be easily fabricated even if it is not readily available. If required, the solenoid used in electrical gong type of bell may be used for the purpose.

Copyright : EFY

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Computerised Universal Timer

This simple and flexible timer is more accurate than the real-time clock of the computer used for the purpose. It can be used in laboratories, dark rooms, kitchens, and for competitions in educational institutes. The program written in Q-Basic is self-explanatory. Generally, a universal timer provides the facility for switching on an electrical/electronic device after elapse of a certain time period, say, 5 minutes. The software does the same job here.

 

Circuit diagram :

Computerised Universal Timer Circuit Diagram

 

When the program is executed, it displays 0:0:0 on the monitor, indicating 0 hour, 0 minute, and 0 second. The display time 0:0:0 is increased by 10 seconds each time function key F1 of the computer keyboard is depressed. So by depressing function key F1 the required time is set for which the electrical or electronic device is to be switched on. However, in debate competitions the time allowed for a candidate to speak is filled the way it is discussed above. The program may be changed as indicated by REM statements and the single quote (‘) in the beginning of a program line may be accordingly removed in the program.

 

Now, after setting the time in the manner as discussed above, function key F2 of the computer keyboard is depressed to switch on any device. Simultaneously, the countdown of the time in the display box starts. The device will remain on until the display box shows 0:0:0 and then it will get switched off. The figure shows the relay interface circuit connected between D0 line (pin 2) and ground line (pin 25) of 378H output port of LPT1 printer port of the computer.

 

Author : D.K. Kaushik - Copyright : EFY

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One second Audible Clock Circuit

Accurate, finger-operated portable unit, 3 - 12V Battery supply

This accurate one-pulse-per-second clock is made with a few common parts and driven from a 50 or 60 Hertz mains supply but with no direct connection to it. A beep or metronome-like click and/or a visible flash, will beat the one-second time and can be useful in many applications in which some sort of time-delay counting in seconds is desirable. The circuit is formed by a CMos 4024 counter/divider chip and 3 diodes, arranged to divide the frequency of the input signal at pin #1 by 50 (or 60, see Notes). The input impedance at pin #1 is very hight, so simply touching the pin (or a short track or piece of wire connected to it) is usually enough to provide the necessary input signal. Another way to provide an input signal consists in a piece of wire wrapped several times around any convenient mains cable or transformer. No other connection is necessary.

Circuit diagram :

One second Audible Clock Circuit Diagram

Parts:

R1 = 10K
R2 = 47.K
R3 = 100R
C1 = 1nF-63V
C2 = 10µF-25V
C3 = 100nF-63V
D1 = 1N4148
D2 = 1N4148
D3 = 1N4148
D4 = LED-(Optional, any shape and color, see Notes)
D5 = 1N4148-75V 150mA Diode (Optional, see Notes)
Q1 = BC337-45V 800mA NPN Transistor
IC1 = 4024-7 stage ripple counter IC
BZ1 = Piezo sounder (incorporating 3KHz oscillator)
SPKR = 8 Ohm, 40 - 50mm diameter Loudspeaker (Optional, see Notes)
SW1 = SPST Toggle or Slide Switch (Optional, see Notes)
B1 = 3 to 12V Battery (See Notes)

Notes:

• To allow precise circuit operation in places where the mains supply frequency is rated at 60Hz, the circuit must be modified as follows: disconnect the Cathode of D1 from pin #11 of IC1 and connect it to pin #9. Add a further 1N4148 diode, connecting its Anode to R1 and the Cathode to pin #6 of IC1: that's all!
• The circuit will work fine with battery voltages in the 3 -12V range.
• The visual display, formed by D4 and R3 is optional. Please note that R3 value shown in the Parts list is suited to low battery voltages. If 9V or higher voltages are used, change its value to 1K.
• If a metronome-like click is needed, R2 and BZ1 must be omitted and substituted by the circuit shown enclosed in dashed lines, right-side of the diagram.
• Stand-by current drawing is negligible, so SW1 can be omitted.

Source : www.redcircuits.com

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A Very Useful Timed Beeper Circuit Schematic

Beeps 7.5 seconds after a preset time, Adjustable time settings: 15s. 30s. 1min. & others

This circuit is intended for alerting purposes after a certain time is elapsed. It is suitable for table games requiring a fixed time to answer a question, or to move a piece etc. In this view it is a modern substitute for the old sandglass. Useful also for time control when children are brushing teeth (at least two minutes!), or in the kitchen, and so on.
Circuit diagram:

Timed Beeper Circuit Diagram

Parts:
R1 = 220R
R2 = 10M
R3 = 1M
R4 = 10K
R5 = 47K
C1 = 100nF-63V
C2 = 22µF-25V
D1 = 1N4148
D2 = 3mm. Red LED
Q1 = BC337
P1 = SPST Pushbutton (Start)
P2 = SPST Pushbutton (Reset)

PS = Piezo sounder (incorporating 3KHz oscillator)
B1 = 3V Battery (2 AA 1.5V Cells in series)
IC1 = CD4081 Quad 2 input AND Gate IC
IC2 = CD4060 14 stage ripple counter and oscillator IC
SW1 = 4 ways Switch (See notes)

Circuit operation:
Pushing on P1 resets IC2 that start oscillating at a frequency fixed by R3 & C1. With values shown, this frequency is around 4Hz. LED D2, driven by IC1A & B, flashing at the same oscillator frequency, will signal proper circuit operation. SW1 selects the appropriate pin of IC2 to adjust timing duration:

• Position 1 = 15 seconds
• Position 2 = 30 seconds
• Position 3 = 1 minute
• Position 4 = 2 minutes

When the selected pin of IC2 goes high, IC1C drives Q1 and the piezo sounder beeps intermittently at the same frequency of the LED. After around 7.5 seconds pin 4 of IC2 goes high and IC1D stops the oscillator through D1. If you want to stop counting in advance, push on P2.

Notes:

1. SW1 can be any type of switch with the desired number of ways. If you want a single fixed timing duration, omit the switch and connect pins 9 & 13 of IC1 to the suitable pin of IC2.
2. The circuit's reset is not immediate. Pushing P2 forces IC2 to oscillate very fast, but it takes some seconds to terminate the counting, especially if a high timer delay was chosen and the pushbutton is operated when the circuit was just starting. In order to speed the reset, try lowering the value of R5, but pay attention: too low a value can stop oscillation.
3. Frequency operation varies with different brand names for IC2. E.g. Motorola's ICs run faster, therefore changing of C1 and/or R3 values may be necessary.
4. You can also use pins 1, 2, 3 of IC2 to obtain timings of 8, 16 and 32 minutes respectively.
5. An on-off switch is not provided because when off-state the circuit draws no significant current.

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A Bedside Lamp Timer Circuit Schematic

30 minutes operation, Blinking LED signals 6 last minutes before turn-off

The purpose of this circuit is to power a lamp or other appliance for a given time (30 minutes in this case), and then to turn it off. It is useful when reading at bed by night, turning off the bedside lamp automatically in case the reader falls asleep... After turn-on by P1 pushbutton, the LED illuminates for around 25 minutes, but then it starts to blink for two minutes, stops blinking for two minutes and blinks for another two just before switching the lamp off, thus signaling that the on-time is ending. If the user want to prolong the reading, he/she can earn another half-hour of light by pushing on P1. Turning-off the lamp at user's ease is obtained by pushing on P2.
Circuit diagram:

A Bedside Lamp Timer Circuit Diagram

Parts:
Resistors
R1 = 1K
R2 = 4K7
R3 = 10M
R4 = 1M
R5 = 10K

Capacitors
C1 = 470µF-25V
C2-C4100nF-63V

Semiconductors
C1 = 470µF-25V
C2-C4 = 100nF-63V
D1-D4 = 1N4002
D5 = 5mm. Red LED
IC1 = CD4012
IC2 = CD4060
Q1 = BC328
Q2 = BC547

Miscellaneous
P1,P2 = SPST Pushbuttons
T1 = 9+9 Volt Secondary 1VA Mains transformer
RL1 = 10.5V 470 Ohm Relay with SPDT 2A 220V switch
PL1 = Male Mains plug
SK1 = Female Mains socket

Circuit operation:
Q1 and Q2 form an ALL-ON ALL-OFF circuit that in the off state draws no significant current. P1 starts the circuit, the relay is turned on and the two ICs are powered. The lamp is powered by the relay switch, and IC2 is reset with a positive voltage at pin 12. IC2 starts oscillating at a frequency set by R4 and C4. With the values shown, pin 3 goes high after around 30 minutes, turning off the circuit via C3. During the c6 minutes preceding turn-off.

The LED does a blinking action by connections of IC1 to pins 1, 2 & 15 of IC2. Blinking frequency is provided by IC2 oscillator at pin 9. The two gates of IC1 are wired in parallel to source more current. If required, a piezo sounder can be connected to pins 1 & 14 of IC1. Obviously, timings can be varied changing C4 and/or R4 values.

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Alarm Clock With Day Selector

This circuit disables an alarm clock on Saturdays and Sundays when people like to sleep in but enables normal operation on Mondays to Fridays so that people rise in time for work or school. The core of the circuit is a 4017 decade counter which acts as the day counter and it is used in conjunction with a desk clock which acts the alarm and a watch module with alarm function which provides one clock pulse very day to the 4017. In operation, the watch module feeds a day pulse via transistor Q3 to the clock input of IC1. This has seven outputs connected via day switches (S1-S7) and diodes D3-D9 to Q1 which disables the alarm signal to the speaker via transistor Q2. LEDs1-7 indicate the actual day (if you forget!).

Circuit diagram:

Alarm Clock With Day Selector Circuit Diagram

To set the system, set the desk clock for the correct time and for the desired alarm time (eg, 6’o’clock). The watch module is set to the correct time and its alarm set to midnight. The day counter, IC1, is set to the correct day, as indicated by the LEDs, by pushing switch S12 and closing switch S8 or S9. S8 is normally left open to conserve the battery by leaving the LEDs off. As shown on the circuit, switches S1-S7 are set to sound the alarm on Mondays to Fridays and disable it on Saturday and Sunday. However, you can change the days to suit your work habits.

Author: Rasim Kucalovic
Copyright: Silicon Chip Electronics

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