กระทู้รวมวงจร 1

กลุ่มวงจอีเล็กทรอนิกส์ทั่วๆไป

Moderator: gang

ภาพประจำตัวสมาชิก
gang
Master of the Order[ ผู้ดูแลระบบ]
Master of the Order[ ผู้ดูแลระบบ]
โพสต์: 1023
ลงทะเบียนเมื่อ: 11/08/2004 11:00 pm
ที่อยู่: บางน้ำผึ้ง พระประแดง สมุทรปราการ
ติดต่อ:

re: กระทู้รวมวงจร 1

โพสต์โดย gang » 31/07/2005 11:34 am

AM Broadcast Transmitter
In this circuit, a 74HC14 hex Schmitt trigger inverter is used as a square wave oscillator to drive a small signal transistor in a class C amplifier configuration. The oscillator frequency can be either fixed by a crystal or made adjustable (VFO) with a capacitor/resistor combination. A 100pF capacitor is used in place of the crystal for VFO operation. Amplitude modulation is accomplished with a second transistor that controls the DC voltage to the output stage. The modulator stage is biased so that half the supply voltage or 6 volts is applied to the output stage with no modulation. The output stage is tuned and matched to the antenna with a standard variable 30-365 pF capacitor. Approximately 20 milliamps of current will flow in the antenna lead (at frequencies near the top of the band) when the output stage is optimally tuned to the oscillator frequency. A small 'grain of wheat' lamp is used to indicate antenna current and optimum settings. The 140 uH inductor was made using a 2 inch length of 7/8 inch (OD) PVC pipe wound with 120 turns of #28 copper wire. Best performance is obtained near the high end of the broadcast band (1.6 MHz) since the antenna length is only a very small fraction of a wavelength. Input power to the amplifier is less than 100 milliwatts and antenna length is 3 meters or less which complies with FCC rules. Output power is somewhere in the 40 microwatt range and the signal can be heard approximately 80 feet. Radiated power output can be approximated by working out the antenna radiation resistance and multiplying by the antenna current squared. The radiation resistance for a dipole antenna is 80*pi^2*(length/wavelength)^2 which yields about 0.2 ohms for a 3 meter dipole at a frequency of 1.6 MHz. Radiated power at 20 milliamps is about I^2 * R = 80 microwatts and for a grounded system with a single element whip antenna, the radiated power is about half that, or 40 microwatts.

Parts List:
Resistor 330 01
Resistor 1K 03
Resistor 25K Pot 01
Resistor 5.1K 01
Resistor 220 01
Capacitor 100pF 01
Capacitor 0.1uF 03
Capacitor 100uF 01
Capacitor 330pF 01
Capacitor 30-300pF Trim. 01
Zener 5.1V 01
IC 74HC14 01
Inductor 1mH 01
Inductor 140uH 01
แนบไฟล์
PICT0274.GIF
PICT0274.GIF (4.26 KiB) เปิดดู 13171 ครั้ง
แก้ไขล่าสุดโดย 1 เมื่อ gang, แก้ไขแล้ว 31 ครั้ง.
I Love Arduino

ภาพประจำตัวสมาชิก
gang
Master of the Order[ ผู้ดูแลระบบ]
Master of the Order[ ผู้ดูแลระบบ]
โพสต์: 1023
ลงทะเบียนเมื่อ: 11/08/2004 11:00 pm
ที่อยู่: บางน้ำผึ้ง พระประแดง สมุทรปราการ
ติดต่อ:

re: กระทู้รวมวงจร 1

โพสต์โดย gang » 31/07/2005 11:36 am

Audio Amplifier - 3 Transistor
Here is a little audio amplifier similar to what you might find in a small transistor radio. The input stage is biased so that the supply voltage is divided equally across the two complimentary output transistors which are slightly biased in conduction by the diodes between the bases. A 3.3 ohm resistor is used in series with the emitters of the output transistors to stabilize the bias current so it doesn't change much with temperature or with different transistors and diodes. As the bias current increases, the voltage between the emitter and base decreases, thus reducing the conduction. Input impedance is about 500 ohms and voltage gain is about 5 with an 8 ohm speaker attached. The voltage swing on the speaker is about 2 volts without distorting and power output is in the 50 milliwatt range. A higher supply voltage and the addition of heat sinks to the output transistors would provide more power. Circuit draws about 30 milliamps from a 9 volt supply.
Parts List:
Resistor 470 01
Resistor 5.6K 01
Resistor 3.3 02
Resistor 1.5K 01
Resistor 22 01
Capacitor 1000uF 01
Capacitor 47uF 01
Diode 1N4148 02
Transistor 2N3053 02
Transistor 2N2905 01
แนบไฟล์
PICT0278.GIF
PICT0278.GIF (2.18 KiB) เปิดดู 13167 ครั้ง
แก้ไขล่าสุดโดย 1 เมื่อ gang, แก้ไขแล้ว 31 ครั้ง.
I Love Arduino

ภาพประจำตัวสมาชิก
gang
Master of the Order[ ผู้ดูแลระบบ]
Master of the Order[ ผู้ดูแลระบบ]
โพสต์: 1023
ลงทะเบียนเมื่อ: 11/08/2004 11:00 pm
ที่อยู่: บางน้ำผึ้ง พระประแดง สมุทรปราการ
ติดต่อ:

re: กระทู้รวมวงจร 1

โพสต์โดย gang » 31/07/2005 11:40 am

FM Stereo Transmitter - Crystal Controlled
Parts List:
Resistor 1K 09
Resistor 8.2K 02
Resistor 22K 07
Resistor 47K 04
Resistor 100K 05
Resistor 68K 04
Resistor 2.2K 04
Resistor 10K Pot 01
Resistor 25K Pot 01
Resistor 3.3K 02
Resistor 2.2M 01
Resistor 220 01
Resistor 470 03
Resistor 220K 01
Resistor 1M 01
Resistor 330 01
Resistor 1K Pot 01
Resistor 6.8K 01
Resistor 10K 01
Resistor 4.7K 01
Resistor 1.5K 01
Resistor 33 01
Resistor 58 01
Capacitor 470pF 03
Capacitor 68pF 01
Capacitor 120pF 01
Capacitor 47pF 01
Capacitor 0.01uF 11
Capacitor 1uF, 50V 04
Capacitor 100uF, 16V 03
Capacitor 12pF 01
Capacitor 33pF 01
Capacitor 470uF, 16V 01
Capacitor 2-20pF Trim. 01
Capacitor 39pF 01
Capacitor 0.1uF 01
Capacitor 100pF 01
Capacitor 18pF 01
Crystal 4.864MHz 01
Crystal 10.240MHz 01
Diode MV2107 01
Diode 1N757A 01
Diode 1N4007 01
Transistor MPF102 01
Transistor 2N3563 03
Transistor MPS3866 01
IC LM1458 01
IC LM1496 01
IC 74C00 01
IC CD404D 01
IC MC145151-2 01
IC CA3420 01
IC 74F160 01
Regulator LM7805 01
แนบไฟล์
PICT0281.GIF
PICT0281.GIF (47.77 KiB) เปิดดู 13165 ครั้ง
I Love Arduino

ภาพประจำตัวสมาชิก
gang
Master of the Order[ ผู้ดูแลระบบ]
Master of the Order[ ผู้ดูแลระบบ]
โพสต์: 1023
ลงทะเบียนเมื่อ: 11/08/2004 11:00 pm
ที่อยู่: บางน้ำผึ้ง พระประแดง สมุทรปราการ
ติดต่อ:

re: กระทู้รวมวงจร 1

โพสต์โดย gang » 31/07/2005 11:43 am

Passive Aircraft Receiver
The Passive Aircraft Receiver is an amplified 'crystal radio' designed to receive AM aircraft transmissions. The 'passive' design uses no oscillators or other RF circuitry capable of interfering with aircraft communications. Nevertheless, check the regulations before using this receiver on a commercial airliner.

The detector diode should be a germanium detector diode similar to the 1N34 or a schottky small signal diode like the 1N5711 or HP2835. The 10M resistors provide a small diode bias current for better detector efficiency.

The tuning capacitor may be any small variable with a range from about 5 pF to about 15 or 20 pF. The 0.15uH inductor may be a molded choke or a few turns wound with a small diameter. Experiment with the coil to get the desired tuning range. The aircraft frequencies are directly above the FM band so a proper inductor will tune FM stations with the capacitor set near maximum capacity. (The FM stations will sound distorted since they are being slope detected.) Other capacitor and inductor combinations may be selected to tune other bands if desired. (Try the CB band at 27 MHz.)

The LM358 dual op-amp draws under 1mA so the battery life is quiet long. A speaker amplifier may be added to drive a speaker or low-z earphone. Consider operating the speaker amplifier from a separate battery to preserve stability.

The antenna can be a couple of inches if the receiver is near the transmitter or a couple of feet for maximum range. The selectivity is reduced as the antenna length is increased so best performance is achieved with the shortest acceptable antenna. Try increasing the 1.8pF capacitor value when using very short antennas and decreasing it for long antennas. The receiver could be built into a small plastic box with a short antenna inside

* This 100 uF capacitor is not critical and larger or smaller values will work well. If a speaker amplifier is powered from the same battery as the op-amp then add a 100 ohm resistor between the battery and the op-amp power. Power the speaker amp directly from the battery with another large electrolytic capacitor from power to ground.
** A smaller capacitor, say 10 uF, is adequate if the earphone is a high-z type as recommended. A crystal earphone only needs 1 uF or even less. The 100 uF is "overkill" for most earphones. (An 8 ohm speaker needs about 100 uF for voice audio.) The minimum recommended value is 1000/Z in microfarads where Z is the earphone impedance. A 500 ohm headset would need: 1000/500 = 2uF.
*** The 3.3 k resistors may be lowered a bit for more gain but increase the 1 uF capacitors to 4.7 uF to preserve the low frequency response.

Parts List:
Resistor 10M 02
Resistor 100K Pot 01
Resistor 3.3K 02
Resistor 100K 01
Resistor 100 01
Capacitor 1.5pF 01
Capacitor 5-18pF Trim. 01
Capacitor 0.01uF 01
Capacitor 330pF 01
Capacitor 100uF 02
Capacitor 1uF 02
Inductor 0.15uH 01
Diode 1N34 01
IC LM358 02
แนบไฟล์
pict0284.gif
pict0284.gif (20.94 KiB) เปิดดู 13159 ครั้ง
แก้ไขล่าสุดโดย 1 เมื่อ gang, แก้ไขแล้ว 31 ครั้ง.
I Love Arduino

ภาพประจำตัวสมาชิก
gang
Master of the Order[ ผู้ดูแลระบบ]
Master of the Order[ ผู้ดูแลระบบ]
โพสต์: 1023
ลงทะเบียนเมื่อ: 11/08/2004 11:00 pm
ที่อยู่: บางน้ำผึ้ง พระประแดง สมุทรปราการ
ติดต่อ:

re: กระทู้รวมวงจร 1

โพสต์โดย gang » 31/07/2005 11:45 am

Personal AM Radio Station
Most values are not critical but a few choices must be made carefully for best results. The output tank is tuned to the crystal frequency by selecting the values from the chart. For example, for a 1 MHz transmitter, the chart indicates 500 pf and 35 uh. This chart assumes that a 220 pf capacitor is already connected between the collector and base of the output transistor as indicated in the schematic so the indicated capacitance is in addition to the 220 pf. A variable inductor or capacitor will allow the tank to be fine-tuned for the maximum meter reading with no antenna connected (a few volts with a 10 megohm voltmeter or about 50 microamps with a current meter). After the antenna is connected, the loading inductor in series with the antenna is selected for the minimum meter reading (best antenna loading). (A 3 foot antenna will need about 820 uH for a 1.6 MHz output frequency.) Longer antennas or higher frequencies need less inductance and shorter antennas or lower frequencies will need more. The meter reading should drop by more than half with a reasonably good antenna but the reading can be ignored if sufficient transmit range is achieved. The antenna, which is short relative to the wavelength, is hard to match well because it has a very low radiation resistance in series with a very small capacitor. (The power dissipated in the radiation resistance is the power that is transmitted.) The loading coil helps to resonate out some of the series capacity resulting in more antenna current and thus more radiated power. Some retuning of the tank may be desirable when the loading coil value is changed. A remote radio playing back through a baby monitor or walkie-talkie makes a good signal quality monitor for antenna tuning and positioning. The crystal can be practically any surplus crystal with a fundamental frequency between 530 kHz and 1.7 MHz in 10 kHz increments but the higher frequencies work best. Choose a crystal frequency away from strong local stations at or above 800 kHz for best transmit range. Proper operation of the oscillator may be verified by probing the junction of the two 1000 pf capacitors with a high impedance oscilloscope probe connected to a scope or frequency counter. Full modulation is achieved by applying about 2 volts peak-to-peak to the base of the current source transistor in the differential amplifier. The modulation voltage varies the current in the diff. amp. away from the nominal 20 ma. setpoint and this modulated current is converted to a clean, high voltage sinewave by the output tuning circuit. The modulated signal may be observed with an oscilloscope connected to the antenna terminal if desired. Circuit construction is mostly non-critical but a few points should be observed. Ground-plane is not mandatory but it helps control parasitic feedback elements when less than perfect layout techniques are used. The two capacitors across the base-collector leads of the diff-amp transistors should have short leads. Bypass the 15 volt supply well, perhaps with additional 1 uf capacitors not shown in the schematic. The 100 ohm emitter resistor in the modulator may be bypassed with a 22 ohm resistor in series with a 470 uf capacitor to increase the modulation sensitivity to about 1 volt peak-to-peak which is typical of many sources. Eliminating the 22 ohm resistor will increase sensitivity to under 100 mv but the linearity will suffer somewhat. An amplifying audio mixer may be added as shown in fig. 2 if more than one audio source is to be used. The gain resistor might be near 2.8k for typical 300 mv sources or considerably higher for lower level sources. If the signal level is different for each source then vary the 600 ohm resistors to compensate. A larger resistor will reduce the gain. Set the main gain resistor for the weakest source then increase the 600 ohm resistors in the other channels for the proper balance. A fancy mixer panel could be constructed with potentiometers in place of the resistors. Remember that some op-amps are not sufficiently fast to amplify high fidelity audio. For simplicity, choose an internally-compensated audio op-amp such as the LM833. Since the LM833 is a dual op-amp the second amp could be used as a separate pre-amp for a microphone or other low-level sources using the same schematic as the mixer. The output of this amp simply feeds one of the mixer source inputs.

In this circuit, the final radio frequency stage is the transistor connected to the output tank. This transistor conducts one-half of the bias current flowing through the modulator transistor which is set to 20 ma in the circuit as shown. This current may be determined by measuring the voltage across the 100 W resistor. The output transistor drops about two-thirds of the power supply voltage which is 10 volts with the 15 volt supply. The power dissipated in the output stage is therefore 10 ma times 10 volts which is the legal limit of 100 mw. An antenna 9.8 feet long is the legal limit and is more than adequate if a proper loading choke is selected. In fact, an antenna only a few feet long is more manageable and may be adequate in many applications. Harmonic content of the circuit as shown was measured at the output terminal to be 27 dB below the carrier when tested at 1.6 MHz. If the tank values are selected near the values suggested by the chart, similar performance should be achieved. The connection of a properly loaded antenna will further filter the radiated signal so the device should be well inside the technical requirements.
Parts List:
Resistor 8.2K 01
Resistor 47K 01
Resistor 39 01
Resistor 470 02
Resistor 330 01
Resistor 10K 01
Resistor 2.7K 02
Resistor 1.8K 02
Resistor 22 01
Resistor 2.2K 02
Resistor 100 01
Resistor 100K 02
Capacitor 1000pF 02
Capacitor 10uF 01
Capacitor 0.1uF 06
Capacitor 39pF 01
Capacitor 3.3uF 02
Capacitor 220pF 01
Diode 1N914 01
Transistor 2N4401 03
แนบไฟล์
pict0285.gif
pict0285.gif (22.87 KiB) เปิดดู 13150 ครั้ง
I Love Arduino

ภาพประจำตัวสมาชิก
farmzaa
Rookie
Rookie
โพสต์: 17
ลงทะเบียนเมื่อ: 01/01/1970 7:00 am

re: กระทู้รวมวงจร 1

โพสต์โดย farmzaa » 02/03/2006 2:27 pm

8)

ภาพประจำตัวสมาชิก
farmzaa
Rookie
Rookie
โพสต์: 17
ลงทะเบียนเมื่อ: 01/01/1970 7:00 am

re: กระทู้รวมวงจร 1

โพสต์โดย farmzaa » 02/03/2006 2:28 pm

:D

ภาพประจำตัวสมาชิก
farmzaa
Rookie
Rookie
โพสต์: 17
ลงทะเบียนเมื่อ: 01/01/1970 7:00 am

re: กระทู้รวมวงจร 1

โพสต์โดย farmzaa » 02/03/2006 2:29 pm

8O สุดยอด

ลำปางหนาวมาก

โพสต์โดย ลำปางหนาวมาก » 11/11/2008 8:46 am

มีวงจรตู้แอมป์เบสมั้ยครับ ซัก 50 Watt

ขอบคุณมากครับ

baba

โพสต์โดย baba » 06/07/2009 6:41 pm

ผมมีแร่ X-TAL 4.8640 MHZ จำหน่ายครับ ติดต่อได้ที่ 105.00mhz@gmail.com :oops:

baba

โพสต์โดย baba » 06/07/2009 6:47 pm

เพิ่มเติม
ชุดเครื่องส่ง MPX96 ทั้งชุดมีชุดคิด และอุปกรณ์จำหน่ายครบทุกเบอร์ครับ พร้อมคู่มือการปรับแต่งให้ส่งได้ทุกย่าน 88 - 108 MHZ :roll: :P :roll:

ภาพประจำตัวสมาชิก
tanapatxxx
Rookie
Rookie
โพสต์: 2
ลงทะเบียนเมื่อ: 01/01/1970 7:00 am

โพสต์โดย tanapatxxx » 24/09/2009 9:20 pm

ขอบคุณมากครับ สำหรับน้ำใจดีๆ

pratchaya.aut
Rookie
Rookie
โพสต์: 2
ลงทะเบียนเมื่อ: 07/09/2010 12:13 am

Re: กระทู้รวมวงจร 1

โพสต์โดย pratchaya.aut » 07/09/2010 4:23 pm

Good!!!!


ย้อนกลับไปยัง

ผู้ใช้งานขณะนี้

กำลังดูบอร์ดนี้: 5 และ บุคคลทั่วไป 0 ท่าน

cron