HOW TO MAKE A TAN TIMER

This timer was designed for people wanting to get tanned but at the same time wishing to avoid an excessive exposure to sunlight.

A Rotary Switch sets the timer according to six classified Photo-types (see table).

A Photo resistor extends the preset time value according to sunlight brightness (see table).

When preset time ends, the beeper emits an intermittent signal and, to stop it, a complete switch-off of the circuit via SW2 is necessary.

Photo-type	Features	Exposure time
I & children	Light-eyed, red-haired, light complexion, freckly	20 to 33 minutes
II	Light-eyed, fair-haired, light complexion	28 to 47 minutes
III	Light or brown-eyed, fair or brown-haired, light or slightly dark complexion	40 to 67 minutes
IV	Dark-eyed, brown-haired, dark complexion	52 to 87 minutes
V	Dark-eyed, dark-haired, olive complexion	88 to 147 minutes
VI	The darkest of all	136 to 227 minutes
Note that pregnant women belong to Photo-type I

Components Used

R1_____________47K   1/4W Resistor
R2______________1M   1/4W Resistor
R3,R5_________120K   1/4W Resistors
R4____________Photo resistor (any type)

C1,C3__________10µF   25V Electrolytic Capacitors
C2____________220nF   63V Polyester Capacitor

D1,D2________1N4148   75V 150mA Diodes

IC1____________4060  14 stage ripple counter and oscillator IC
IC2____________4017  Decade counter with 10 decoded outputs IC

Q1____________BC337   45V 800mA  NPN Transistor
SW1___________2 poles 6 ways Rotary Switch (see notes)
SW2___________SPST  Slider Switch

BZ1___________Piezo sounder (incorporating 3KHz oscillator)

B1____________3V Battery (two 1.5V AA or AAA cells in  series etc.)

NOTES

• Needing only one time set suitable for your own skin type, the rotary switch can be replaced by hard-wired links.

• A DIP-Switch can be used in place of the rotary type. Please pay attention to use only one switch at a time when the device is off, or the ICs could be damaged.

Electronic Sleep Inducer

Many people experienced sleeping well in natural surroundings, into a tent or a wooden hut. This fact is due not only to the healthy atmosphere but also from our unconscious ability to perceive natural Earth ’s magnetic -fields. The circuit generates this type of Geo-magnetic-fields and lets us perceive them: in this manner our brain is surrounded by an ideal environment for a sound sleep.

Features Of Sleep Inducer

* Generates a natural electromagnetic-field

* Makes easier to fall asleep

* Induces a prolonged and sound sleep without drugs

* No side effects

How To Use The Circuit

Select a timing option by means of the rotary switch SW1.

Choose 15, 30 or 60 minutes operation.

Select “Stop” or “Alternate” mode operation by means of SW2.

With SW2 closed (Stop mode operation) the electromagnetic radiation stops after the pre-set time is elapsed.

With SW2 opened (Alternate mode operation) the device operates for the pre-set time, then pauses for the same amount of time: this cycle repeats indefinitely.

Place the unit under the pillow and sleep like a log.

To reset a cycle press P1 push button.

Working Of Circuit

IC2C and IC2D generate two square waves at about 1.2 and 5 Hz respectively. These wave-forms are converted into 60µS pulses at the same frequencies by means of C5 & C6 and mixed at Q1 Base. This transistor drives the Radiator coil with a scalar series of pulses of 60µS length and 9V amplitude.

IC1, IC2A & IC2B form the timer section. C1 & R2 provide auto-reset of IC1 at switch-on. The internal oscillator of IC1 drives the 14 stage ripple counter and, after about 15 minutes, output pin 1 goes high. Pin 3 of IC2A goes low and stops IC2C & IC2D oscillation.

If SW2 is left open (Alternate mode operation), after 15 minutes pin 1 of IC1 goes low, pin 3 of IC2A goes high and oscillators are enabled again.

If SW2 is closed (Stop mode operation), the first time output pin 1 of IC1 goes high, the internal oscillator of the IC is disabled by means of D1. Therefore the circuit remains off until a reset pulse is applied to pin 12 by means of P1 or when the whole device is switched-off and then restarted.

The same thing occurs when SW1 is switched on 30 or 60 minutes positions, obviously changing time length.
IC2B drives pilot LED D2 which operates in the following three modes:

Flashes quickly and almost randomly when the Radiator coil is driven

Flashes somewhat slowly and regularly when the Radiator coil is pausing during the Alternate mode operation

Is off when the circuit auto-stops (Stop mode operation)

Components Used

R1,R5___________1K   1/4W Resistors
R2_____________10K   1/4W Resistor
R3,R6__________10M   1/4W Resistors
R4,R7___________2M2  1/4W Resistors
R8,R9___________4K7  1/4W Resistors

C1,C7__________47µF   25V Electrolytic Capacitors
C2____________100nF   63V Polyester Capacitor
C3,C4_________330nF   63V Polyester Capacitors
C5,C6__________15nF   63V Polyester Capacitors

D1,D3,D4,D5__1N4148   75V 150mA Diodes
D2______________LED   (any type) (see Notes)

IC1____________4060  14 stage ripple counter and oscillator IC
IC2____________4093  Quad 2 input Schmitt NAND Gate IC

Q1____________BC327   45V 800mA PNP Transistor

L1____________Radiator coil (see Notes)

P1____________SPST  Pushbutton

SW1___________2 poles 4 ways rotary switch
SW2___________SPST  Slider Switch

B1____________9V PP3 Battery

Clip for PP3 Battery

Notes

L1 is obtained by winding randomly 600 turns of 0.2 mm. enameled wire on a 6 mm. diameter, 40 mm. long, steel bolt. Secure the winding with insulating tape.

Mean current drawing is about 7mA, decreasing to less than 4mA during pauses when in Alternate mode operation.

Battery life can be dramatically increased omitting LED D2 and its associated resistor R5.

Use a plastic box to enclose the circuit: metal cases can severely limit electromagnetic radiation.

IMPROVED VERSION OF MUSCULAR BIO STIMULATOR-BIOMEDICAL PROJECTS

This circuit is a big improvement of the small Muscular Bio-Stimulator design

DOWNLOAD THE CIRCUIT DIAGRAM

COMPONENTS REQUIRED

P1_____________100K  Linear Potentiometer
P2,P3___________10K  Linear Potentiometers

R1_____________560K  1/4W Resistor
R2______________68K  1/4W Resistor
R3,R4___________10K  1/4W Resistors
R5______________22K  1/4W Resistor
R6,R7____________4K7 1/4W Resistors
R8_____________330R  1/4W Resistor
R9_______________2K2 1/4W Resistor
R10____________470R  1/4W Resistor
R11_____________47R  1/4W Resistor

C1_______________1µF  63V Polyester Capacitor
C2,C3__________100nF  63V Polyester or Ceramic Capacitors
C4_____________220nF  63V Polyester Capacitor
C5_____________220µF  25V Electrolytic Capacitor

D1______________LED  (Any dimension, shape and color)
D2,D3________1N4148   75V 150mA Diodes

Q1____________BC547   45V 100mA NPN Transistor
Q2,Q3_________BC327   45V 800mA PNP Transistors

IC1,IC2________7555 or TS555CN CMos Timer ICs

T1_____________230V Primary, 12V Secondary 1.2VA Mains transformer (see Notes)

SW1,SW2________SPST  Toggle or Slide Switches

Notes:

• T1 is a small mains transformer 230 to 12V @ 100 or 150mA. It must be reverse connected, i.e. the 12V secondary winding across Q3 Collector and negative ground, and the 230V primary winding to P3 and output Electrodes.


• The circuit has been thoroughly tested, and it works nicely when supplied in the 3V - 9V range. Running on 3V supply with a 12V 1.2VA transformer it would be no more dangerous than the circuit already published. But please note that using 9V battery supply it can output 120V signals and could be very dangerous.


• Electrodes can be obtained by small metal plates connected to the output of the circuit via usual electric wire and can be taped to the skin. In some cases, moistening them with little water has proven useful.


• Commercial sets have frequently a built-in 30 minutes timer. For this purpose you can use the Timed Beeper the Bedside Lamp Timer or the Jogging Timer circuits available on this Website, adjusting the timing components to suit your needs.