Automated Crib Lights

Device purpose:

This circuit is intended to drive the various lights decorating the crib prepared during Christmas season at many homes in Latin Countries, especially for children delight, in order to obtain realistic light-effects.


Features:

• Alternating day and night with lights gradually dimming from full-on to full-off and the opposite.
• Slow turn on of model-houses interior as night approaches, and slow turn off as sun rises, with presettable intensity, thus imitating candles' light for a more realistic effect.
• Flickering ever-running circuit driving bulbs for fires, firesides, lanterns effects etc.
• Total cycle duration: 2 minutes. Day duration: 1 minute, 15 seconds. Night duration: 45 seconds. (All values are approximate).

Parts:

• R1___________150K 1/4W Resistor
• R2,R9,R14_____22K 1/4W Resistors
• R3,R11_______220K 1/4W Resistors
• R4,R12________10K 1/4W Resistors
• R5___________100K 1/2W Trimmer Cermet
• R6,R7,R13,R15__1R 1/4W Resistors
• R8____________33K 1/4W Resistor
• R10__________270K 1/4W Resistor
• R16___________47R 1/4W Resistor
• C1,C4________100nF 63V Polyester Capacitors
• C2,C6_________10µF 25V Electrolytic Capacitors
• C3,C5________100µF 25V Electrolytic Capacitors
• D1-D3_______1N4148 75V 150mA Diodes
• IC1___________4060 14 stage ripple counter and oscillator IC
• IC2__________LM324 Low power Quad Op-Amp IC
• IC3__________78L12 12V 100mA Voltage regulator IC
• Q1,Q3,Q5_____BC238 25V 100mA NPN Transistors
• Q2,Q4,Q6_____BD681 100V 4A NPN Darlington Transistors
• J1___________Miniature input socket,
• suited for commercial plug-in variable voltage power supplies
• J2-J5________Two ways output sockets

Load requirements:

• Input J1 is connected to a commercial wall plug-in power supply transformer adapter with variable output settled to 12-15Vdc, and a required minimum output capability of 600mA @ 12V. Using a good number of bulbs the output capability must reach about 1.5A.
• Output J2 is connected to a permanently-on 12V 1W blue bulb(s) for night effect.
• Output J3 is connected to several 12V 2.2W bulbs in parallel for sunlight effect. Max. output current: 1.2A (i.e. 6-7 bulbs).
• Output J4 is connected to several 12V 1W or 1/2W micro-bulbs in parallel for house-interiors lights. Max. output current: 600mA (i.e. 7-8 1W bulbs, doubling in number if 1/2W).
• Output J5 is connected to one or several 12V 1W or 1/2W micro-bulbs in parallel for fires, firesides, lanterns effects etc. Max. output current: 600mA (bulbs total number same as above).
• All outputs are current limited, and short-proof for a reasonable lapse of time.

Circuit operation:

IC1 oscillates at a frequency calculated to obtain a pin 2 level change around every minute. IC2A is then enabled to slowly charge and discharge C5 through R10 during a 2 minutes period. IC1 pin 9 drives D2, R3 & C4, generating a sawtooth for IC2C & IC2D comparators. IC2D comparing the voltage at pin 13 with the sawtooth, generates a squarewave with variable mark-space ratio driving the output darlington Q2 for daylight bulbs. IC2B changes its output at a threshold voltage settled by R8 & R9, activating IC2C & Q4 that act like IC2D & Q2 driving model-houses bulbs as evening approaches and turning them off at dawn. R11 & C6 provide slow turn on and off and R5 sets the basic brightness of these bulbs. IC1 pin 7 drives the output darlington Q6 for flickering fires bulbs and R16 prevents them to turn off completely for a more realistic effect. Q1, Q3, Q5 and associated Base resistors provide current limiting.

Notes:

• Total period length can be varied changing C1 and/or R1 values.
• Day-night ratio can be varied changing R10 value slightly.
• Threshold voltage of turn on and off of model-houses lights can be varied changing slightly R8 and/or R9 values.
• Turn on and off speed of model-houses lights can be varied changing R11 value.
• Current limiting can be varied changing Q2, Q4 & Q6 Emitter resistors.
• Heatsinks for Q2, Q4 & Q6 are needed if current limits are increased.

Universal Input Linear Fluorescent Ballast

Features

• Drives one 35 W TL5 Lamp
• Input Voltage: 80 VAC to 260 VAC
• High Power Factor/Low THD
• High Frequency Operation
• Lamp Filament Preheating
• Lamp Fault Protection with Auto-Restart
• Low AC Line Protection
• End of Lamp Life Shutdown
• IRS2166D(S)PbF HVIC Ballast Controller

The Board is a high efficiency, high power factor, fixed output electronic ballast designed for driving rapid start fluorescent lamp types. The design contains an EMI filter, active power factor correction and a ballast control circuit using the IRS2166D(S)PbF Ballast Control IC1.

The Board consists of an EMI filter, an active power factor correction section, a ballast control section and a resonant lamp output stage. The active power factor correction section is a boost converter operating in critical conduction mode, free-running frequency mode. The ballast control section provides frequency modulation control of a traditional RCL lamp resonant output circuit and is easily adaptable to a wide variety of lamp types. The ballast control section also provides the necessary circuitry to perform lamp fault detection, shutdown and auto-restart.

This board is designed for single TL5/35W Lamp, voltage mode heating (JV1 and JV2 mounted, JC1 and JC2 not mounted). TL5 lamps are becoming more popular due to their lower profile and higher lumen/ watt output. These lamps, however, can be more difficult to control due to their higher ignition and running voltages. A typical ballast output stage using current-mode filament heating (filament placed inside L-C tank) will result in excessive filament current during running. The output stage has therefore been configured for voltage-mode filament heating using secondary windings off of the resonant inductor LRES. The lamp has been placed outside the under-damped resonant circuit loop, which consist of LRES and CRES. The filament heating during preheat can be adjusted with the capacitors CH1 and CH2. The result is a more flexible ballast output stage necessary for fulfilling the lamp requirements. The DC blocking capacitor, CDC, is also placed outside the under-damped resonant circuit loop such that it does not influence the natural resonance frequency of LRES and CRES. The snubber capacitor, CSNUB, serves as charge pump for supplying the IRS2166D.

The IRS2166D Ballast Control IC is used to program the ballast operating points and protect the ballast against conditions such as lamp strike failures, low DC bus, thermal overload or lamp failure during normal operations. It is also used to regulate the DC bus and for power factor control allowing high power factor and low harmonic distortion.

Automatic Room Lights

n ordinary automatic room power control circuit has only one light sensor. So when a person enters the room it gets one pulse and the lights come ‘on.’ When the person goes out it gets another pulse and the lights go ‘off.’ But what happens when two persons enter the room, one after the other? It gets two pulses and the lights remain in ‘off’ state. The circuit described here overcomes the above-mentioned problem. It has a small memory which enables it to automatically switch ‘on’ and switch ‘off’ the lights in a desired fashion. The circuit uses two LDRs which are placed one after another (separated by a distance of say half a metre) so that they may separately sense a person going into the room or coming out of the room. Outputs of the two LDR sensors, after processing, are used in conjunction with a bicolour LED in such a fashion that when a person gets into the room it emits green light and when a person goes out of the room it emits red light, and vice versa.



These outputs are simultaneously applied to two counters. One of the counters will count as +1, +2, +3 etc when persons are getting into the room and the other will count as -1, -2, -3 etc when persons are getting out of the room. These counters make use of Johnson decade counter CD4017 ICs. The next stage comprises two logic ICs which can combine the outputs of the two counters and determine if there is any person still left in the room or not. Since in the circuit LDRs have been used, care should be taken to protect them from ambient light. If desired, one may use readily available IR sensor modules to replace the LDRs.

The sensors are installed in such a way that when a person enters or leaves the room, he intercepts the light falling on them sequentially—one after the other. When a person enters the room, first he would obstruct the light falling on LDR1, followed by that falling on LDR2. When a person leaves the room it will be the other way round. In the normal case light keeps falling on both the LDRs, and as such their resistance is low (about 5 kilo-ohms). As a result, pin 2 of both timers (IC1 and IC2), which have been configured as monostable flip-flops, are held near the supply voltage (+9V).

When the light falling on the LDRs is obstructed, their resistance becomes very high and pin 2 voltages drop to near ground potential, thereby triggering the flip-flops. Capacitors across pin 2 and ground have been added to avoid false triggering due to electrical noise. When a person enters the room, LDR1 is triggered first and it results in triggering of monostable IC1.

The short output pulse immediately charges up capacitor C5, forward biasing transistor pair T1-T2. But at this instant the collectors of transistors T1 and T2 are in high impedance state as IC2 pin 3 is at low potential and diode D4 is not conducting. But when the same person passes LDR2, IC2 monostable flip-flop is triggered. Its pin 3 goes high and this potential is coupled to transistor pair T1-T2 via diode D4. As a result transistor pair T1-T2 conducts because capacitor C5 retains the charge for some time as its discharge time is controlled by resistor R5 (and R7 to an extent).

Thus green LED portion of bi-colour LED is lit momentarily. The same output is also coupled to IC3 for which it acts as a clock. With entry of each person IC3 output (high state) keeps advancing. At this stage transistor pair T3-T4 cannot conduct because output pin 3 of IC1 is no longer positive as its output pulse duration is quite short and hence transistor collectors are in high impedance state. When persons leave the room, LDR2 is triggered first followed by LDR1.

Since the bottom half portion of circuit is identical to top half, this time with the departure of each person red portion of bi-colour LED is lit momentarily and output of IC4 advances in the same fashion as in case of IC3. The outputs of IC3 and those of IC4 (after inversion by inverter gates N1 through N4) are ANDed by AND gates (A1 through A4) are then wire ORed (using diodes D5 through D8). The net effect is that when persons are entering, the output of at least one of the AND gates is high, causing transistor T5 to conduct and energise relay RL1.

The bulb connected to the supply via N/O contact of relay RL1 also lights up. When persons are leaving the room, and till all the persons who entered the room have left, the wired OR output continues to remain high, i.e. the bulb continues to remains ‘on,’ until all persons who entered the room have left. The maximum number of persons that this circuit can handle is limited to four since on receipt of fifth clock pulse the counters are reset.

The capacity of the circuit can be easily extended for up to nine persons by removing the connection of pin 1 from reset pin (15) and utilising Q1 to Q9 outputs of CD4017 counters. Additional inverters, AND gates and diodes will, however, be required.

Running Message Display

Light emitting diodes are advan- tageous due to their smaller size, low current consumption and catchy colours they emit. Here is a running message display circuit wherein the letters formed by LED arrangement light up progressively. Once all the letters of the message have been lit up, the circuit gets reset. The circuit is built around Johnson decade counter CD4017BC (IC2). One of the IC CD4017BE’s features is its provision of ten fully decoded outputs, making the IC ideal for use in a whole range of sequencing operations. In the circuit only one of the outputs remains high and the other outputs switch to high state successively on the arrival of each clock pulse.



The timer NE555 (IC1) is wired as a 1Hz astable multivibrator which clocks the IC2 for sequencing operations. On reset, output pin 3 goes high and drives transistor T7 to ‘on’ state. The output of transistor T7 is connected to letter ‘W’ of the LED word array (all LEDs of letter array are connected in parallel) and thus letter ‘W’ is illuminated. On arrival of first clock pulse, pin 3 goes low and pin 2 goes high. Transistor T6 conducts and letter ‘E’ lights up. The preceding letter ‘W’ also remains lighted because of forward biasing of transistor T7 via diode D21. In a similar fashion, on the arrival of each successive pulse, the other letters of the display are also illuminated and finally the complete word becomes visible. On the following clock pulse, pin 6 goes to logic 1 and resets the circuit, and the sequence repeats itself. The frequency of sequencing operations is controlled with the help of potmeter VR1.

The display can be fixed on a veroboard of suitable size and connected to ground of a common supply (of 6V to 9V) while the anodes of LEDs are to be connected to emitters of transistors T1 through T7 as shown in the circuit. The above circuit is very versatile and can be wired with a large number of LEDs to make an LED fashion jewellery of any design. With two circuits connected in a similar fashion, multiplexing of LEDs can be done to give a moving display effect.

Colour (Sound) Organ

Anyone who has been to a night club, concert or school dance has probobly seen a colour organ. Colour organs cause lights to blink and flash to music from your TV, stereo, guitar and even your own voice. The colour organ presented here needs no connection to the sound source, it picks up sound from its built in microphone.


Schematics


PCB Layout


Parts

• C1 --------- 1 22uf 250V Electrolytic Capacitor
• C2 --------- 1 22uf 250V Electrolytic Capacitor
• C3 --------- 1 0.1uf Disc Capacitor
• C4 --------- 1 0.01uf Disc Capacitor
• C5 --------- 1 0.0047uf Disc Capacitor
• R1 --------- 1 47K 1/2 W Resistor
• R2, R4 ----- 2 6.8K 1/2 W Resistor
• R3, R5 ----- 2 1M 1/2 W Resistor
• R6 ----- 1 3.3K 1/2 W Resistor
• R7, R8, R9 -- 3 1K 1/2 W Resistor
• R10, R11, R12 3 10K Pot
• D1 --------- 1 1N4004 Diode
• Q1, Q2 ----- 2 2N3904 NPN Transistor 2N2222
• Q3, Q4, Q5 - 3 106B1 SCR Teccor S2003LS1
• T1 --------- 1 10K:600 Ohm Audio Transformer
• S1 --------- 1 SPDT Switch
• J1, J2, J3 -- 3 AC Socket
• MISC ------- 1 AC Line Cord, Crystal Microphone, Case, Wire

Notes

• R10, R11 and R12 control the response of the different lights.
• The circuit can handle up to 300 watts per channel.
• This circuit is NOT isolated from the 115 Volt line. If it is used with the case opened or not installed in a case, you could recieve a bad shock or be killed.
• You can also use the Teccor S2003LS1 SCR for SCR1. These give better sensitivity and brightness than the 106B1 units.

12VDC Fluorescent Lamp Driver

A number of people have been unable to find the transformer needed for the Black Light project, so I looked around to see if I could find a fluorescent lamp driver that does not require any special components. Here it is. It uses a normal 120 to 6V stepdown transformer in reverse to step 12V to about 350V to drive a lamp without the need to warm the filaments.


Parts

• C1 ----- 1 100uf 25V Electrolytic Capacitor

• C2,C3 -- 2 0.01uf 25V Ceramic Disc Capacitor
• C4 ----- 1 0.01uf 1KV Ceramic Disc Capacitor
• R1 ----- 1 1K 1/4W Resistor
• R2 ----- 1 2.7K 1/4W Resistor
• Q1 ----- 1 IRF510 MOSFET
• U1 ----- 1 TLC555 Timer IC
• T1 ----- 1 6V 300mA Transformer
• LAMP --- 1 4W Fluorescent Lamp
• MISC --- 1 Board, Wire, Heatsink For Q1

Notes

• Q1 must be installed on a heat sink.
• A 240V to 10V transformer will work better then the one in the parts list. The problem is that they are hard to find.
• This circuit can give a nasty (but not too dangerous) shock. Be careful around the output leads.