Showing posts with label high. Show all posts
Showing posts with label high. Show all posts
Thursday, October 30, 2014
800W high power mosfet amplifier
This amplifier can be used for practically any application that requires high power, low noise, distortion and excellent sound. Examples would be Sub-woofer amp, FOH stage amplifier, One channel of a very high-powered surround sound amplifier etc.
For detail explanation about how this circuit works include the large schematic diagram, power supply schematic diagram and complete component listing, link download this complete article.
Wednesday, October 29, 2014
Advance High Voltage Stun Gun Circuit Diagram
This is an Advance High Voltage Stun Gun Circuit Diagram, This device produces high voltage pulses discrupting muscles and nervous sYstem, leaving anyone who touches it in a state of menthal confusion. Can be used agains ferocious animals or attackers, BUT REMEMBER, this device may be illegal in your state (for eg where I live, these devices are banned). It is quite dangerous for peoples experiencing cardiac problems, and for electronic equipment (like peacemakers), since it generates some RF. Dont attept irresponsible actions with this device, it is not a toy.
Advance High Voltage Stun Gun Circuit Diagram
After the introduction lets pass to the circuit.
The 555 IC is wired as a astable to produce square wave with adjustable freq and duty cycle (notice the potentiometers and diode). This square wave is feed to a IRF840 Mosfet (no need of totem transistors since freq is low and the IC has enough current capability to rapidly charge/discharge the gate). As a substitute of the mosfet, a bipolar transistor can be used (and a 100ohm resistor between 555 and base of the transistor). Valid BJT can be BU406, but also smaller BJT can be ok, keep in mind that it must handle at least 2A continuous. The inductive kick snubber isnt needed because the power is low and it is almost totally adsorbed to charge the tank capacitor, in addition since this device is battery operated we dont want to dissipate the power on a resistor but we want it in sparks. With a snubbing network you will experience lower firing rates.
USE A PUSHBUTTON SWITCH FOR SAFETY
Construction of T2: this is the real boring part. Since it is unlikely to find it in shops we need to build them. Materials needed: enamel copper wire (0,20 mm or 0,125 mm), ferrite stick, LDPE sheets (0,25 mm). Secure the ferrite stick with a layer of ldpe (polyethilene, as a substiture use electric insulating tape) and glue it (or tape it) Place 200-250 windings on the ldpe (even more windings if the stick is more than 1), another ldpe layer, another 200-250 windings and so on to finally have 5-6 layers (approx 1000-1400 turns but even more doesnt hurt performance, but be careful for internar arcing that will ruin it). Insulate it again and place the primary winding, 15-20 turns of 1mm wire are just ok, too much windings (too mush resistance and inductance) will lead to smaller current and smaller spike in T2 secondary because of lower rise time,and too few will not saturate the core. I chosen MKP capacitors because they have low ESR and ESL (they are widely used in tesla coils as mmc capacitors).
The spark gap can be simple two crossed (but not touching) 1 mm spaced wires. It acts as a voltage controlled switch, firing when the voltage is enough to ionize the air between them (turning it to plasma with small resistance). Keep in mind that it would be wise do place it into a small plastic container and fill with oil letting bubbles out (dont use motor oir or frying oil but pure mineral oil which has no water in it.
Construction of T2: this is the real boring part. Since it is unlikely to find it in shops we need to build them. Materials needed: enamel copper wire (0,20 mm or 0,125 mm), ferrite stick, LDPE sheets (0,25 mm). Secure the ferrite stick with a layer of ldpe (polyethilene, as a substiture use electric insulating tape) and glue it (or tape it) Place 200-250 windings on the ldpe (even more windings if the stick is more than 1), another ldpe layer, another 200-250 windings and so on to finally have 5-6 layers (approx 1000-1400 turns but even more doesnt hurt performance, but be careful for internar arcing that will ruin it). Insulate it again and place the primary winding, 15-20 turns of 1mm wire are just ok, too much windings (too mush resistance and inductance) will lead to smaller current and smaller spike in T2 secondary because of lower rise time,and too few will not saturate the core. I chosen MKP capacitors because they have low ESR and ESL (they are widely used in tesla coils as mmc capacitors).
The spark gap can be simple two crossed (but not touching) 1 mm spaced wires. It acts as a voltage controlled switch, firing when the voltage is enough to ionize the air between them (turning it to plasma with small resistance). Keep in mind that it would be wise do place it into a small plastic container and fill with oil letting bubbles out (dont use motor oir or frying oil but pure mineral oil which has no water in it.
Author:Jonathan Filippi, jonathan.filippi@virgilio.it
Monday, October 27, 2014
200W Stereo High Power Amplifier LM3886
This audio amplifier designed uses two LM3886 per channel, in parallel circuit, based on the PA100 parallel amplifier detailed in National Semiconductors application note - AN1192. This amplifier can deliver about 50W into a 8-ohm speaker and 100W into a 4-ohm speaker. This is a stereo amplifier and therefore 4 LM3886s are used.
The LM3886 circuit is in a non-inverted configuration, so the input impedance is determined by the input resistor R1, i.e. 47k. The 680 ohm and 470pF resistor capacitor filter network is used to filter out the high frequency noise at the RCA input. The 220pF C4 and C8 capacitors are used to shot out the high frequency noise at the LM3886 input pins.I used high quality audio grade capacitors at several locations: 1uF Auricap at the input for DC blocking, 100uF Blackgate for C2 and C6, and 1000uF Blackgate at the supply filter.
The PCB is designed in a way that the power ground is separated from the signal ground, as you can see from the below layout. The signal ground is located in the middle and surrounded by the power ground. There is a thin trace near C5 connecting them. The PCB layout is done by using PADS PowerPCB 5.0. I think it is a powerful layout software.
Amplifier Printed Circuit Board (PCB)
Amplifier Power Supply
The power supply used is a regulated power supply. I used 10000uF per rail before the LT1083 regulator. After the regulator, I have 100uF on the regulator board. The advantage of using regulator is that the power supply ripple voltage is removed. If power regulation is not used, I can hear very little 50/100Hz hum from the speaker.
The high current MUR860 diode is used to ensure high current flow. The voltage regulator used is LT1083, it can provide about 8A of current. Transformer used here is a 500VA 2x 25V. The power supply is then regulated by 2 LT1083, after the regulation, the voltage is 30V.
I did some DC measurement and the result is quite good, I got 7 mV of DC offset at the speaker terminal. The voltage difference between the output of the 2 chips is less then 1 mV.
The sound of this amplifier is similar to my LM3875 amplifier, which is very clean and detail. It has no hum, no hiss and no noise. Compared to the LM3875 Gainclone, this amp can deliver twice the power to my 4-ohm speaker, and it improves the dynamics and bass punch a lot.
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| LM3886 Power Amplifier Schematics |
The PCB is designed in a way that the power ground is separated from the signal ground, as you can see from the below layout. The signal ground is located in the middle and surrounded by the power ground. There is a thin trace near C5 connecting them. The PCB layout is done by using PADS PowerPCB 5.0. I think it is a powerful layout software.
Amplifier Printed Circuit Board (PCB)
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| Amplifier Printed Circuit Board Bottom |
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| Amplifier Printed Circuit Board Top |
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| Amplifier Printed Circuit Board |
The power supply used is a regulated power supply. I used 10000uF per rail before the LT1083 regulator. After the regulator, I have 100uF on the regulator board. The advantage of using regulator is that the power supply ripple voltage is removed. If power regulation is not used, I can hear very little 50/100Hz hum from the speaker.
The high current MUR860 diode is used to ensure high current flow. The voltage regulator used is LT1083, it can provide about 8A of current. Transformer used here is a 500VA 2x 25V. The power supply is then regulated by 2 LT1083, after the regulation, the voltage is 30V.
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| Power Supply Recomended |
The sound of this amplifier is similar to my LM3875 amplifier, which is very clean and detail. It has no hum, no hiss and no noise. Compared to the LM3875 Gainclone, this amp can deliver twice the power to my 4-ohm speaker, and it improves the dynamics and bass punch a lot.
Sunday, October 5, 2014
Modular Preamplifier Switching Center
Parts:
R1,R2,R3,R4____100K 1/4W Resistors
R5_____________560R 1/4W Resistor
SW1,SW2________2 poles 4 ways Rotary Switches
J1 to J6_______RCA audio input sockets
Comments:
This module can be a necessary addition to the Modular Preamplifier Control Center when more than two sources need to be connected to the preamplifier chain.
Four high level inputs can be selected by means of SW1 and routed to the output. The output of this module must be connected by a suitable cable to one of the two inputs of the Control Center module. In this way, a total of five inputs will be available to the user of this module combination.
The Switching Control features also the so called "Double Bar", i.e. the possibility of routing to an external unit, e.g. a recorder (tape or digital) an input signal different from that reproduced at the time by the amplifier.
For example, you can listen in to a CD whereas the signal coming from a radio station through the Tuner is routed to the recorder. This selection is operated by means of SW2.
As with the other modules of this series, each electronic board can be fitted into a standard enclosure: Hammond extruded aluminum cases are well suited to host the boards of this preamp. In particular, the cases sized 16 x 10.3 x 5.3 cm or 22 x 10.3 x 5.3 cm have a very good look when stacked. See below an example of the possible arrangement of the front and rear panels of this module.
Wednesday, September 3, 2014
High Voltage Generator Wiring diagram Schematic
This high voltage generator was designed with the aim of testing the electrical break-down protection used on the railways. These protection measures are used to ensure that any external metal parts will never be at a high voltage. If that were about to happen, a very large current would flow (in the order of kilo-amps), which causes the protection to operate, creating a short schema to ground effectively earthing the metal parts. This hap-pens when, for example, a lightning strike hits the overhead line (or their supports) on the railways.
This generator generates a high voltage of 1,000 V, but with an output current that is limited to few milliamps. This permits the electrical breakdown protection to be tested with-out it going into a short schema state. The schema uses common parts throughout: a TL494 pulse-width modulator, several FETs or bipolar switching transistors, a simple 1.4 VA mains transformer and a discrete voltage multiplier. P1 is used to set the maximum current and P2 sets the output voltage.
Circuit diagram :
High Voltage Generator Circuit Diagram
The use of a voltage multiplier has the advantage that the working voltage of the smoothing capacitors can be lower, which makes them easier to obtain. The TL494 was chosen because it can still operate at a voltage of about 7 V, which means it can keep on working even when the batteries are nearly empty. The power is provided by six C-type batteries, which keeps the total weight at a reason-able level.
The 2x4 V secondary of AC power transformer (Tr1) is used back to front. It does mean that the 4 V winding has double the rated voltage across it, but that is acceptable because the frequency is a lot higher (several kilo-Hertz) than the 50 Hz (60 Hz) the transformer is designed for. The final version also includes a display of the output voltage so that the breakdown volt-age can be read.
From a historical perspective there follows a bit of background information. In the past a different system was worked out. Every high-voltage support post has a protection system, and it isn’t clear when the protection had operated and went into a short-schema state due to a large current discharge.
Since very large currents were involved, a certain Mr. Van Ark figured out a solution for this. He used a glass tube filled with a liquid containing a red pigment and a metal ball. When a large current discharge occurred the metal ball shot up due to the strong magnetic field, which caused the pigment to mix with the liquid. This could be seen for a good 24 hours after the event. After a thunder storm it was easy to see where a discharge current took place: one only had to walk past the tubes and have a good look at them.
Unfortunately, things didn’t work out as expected. Since it often took a very long time before a discharge occurred, the pigment settled down too much. When a dis-charge finally did occur the pigment no longer mixed with the liquid and nothing was visible. This system was therefore sidelined, but it found its place in the (railway) history books as the ‘balls of Van Ark’.
Streampowers
Thursday, January 9, 2014
Variable High Pass 20HZ to 200HZ Filter
A simple circuit, High-Pass filter, variable between frequencies 20HZ until 200HZ, useful in a lot of cases elaboration of sound signals. The regulation is achieved with the double potentiometer 47KΩ and the frequency response in his two extreme places, appears in the schematic.
Here continue read..
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| Variable High-Pass 20HZ to 200HZ Filter Circuit Diagram |
Tuesday, December 24, 2013
High Voltage Regulator Circuit Diagram
The High Voltage Regulator Circuit Diagram delivers 100-V at 100 mA and withstands shorts to ground. Even at 100 V output, the LT317A functions in the normal mode, maintaining 1.2 V between its output and adjustment pin. Under these conditions, the 30-V zener is off and Ql conducts. When an output short occurs, the zener conducts, forcing Q1`s base to 30 V.
This causes Q1`s emitter to clamp 2 VnEs below Vz. well within the V.w VouT rating of the regulator. Under these conditions, Q1, a high-voltage device, sustains 90 V-VcE at whatever current the transformer specified saturates at 130 mA, while Q1 safely dissipates 12 W. If Q1 and the LT317 A are thermally coupled, the regulator will soon go into thermal shutdown and oscillation will commence.
This action will continue, protecting the load and the regulator as long as the output remains shorted. The 500-pF capacitor and the 10 0/0.02 11F damper aid transient response and the diodes provide safe discharge paths for the capacitors.
High Voltage Regulator Circuit Diagram
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