Quasar electronics driver#
Quasar electronics full#

The non-inverting (+) input of each comparator is connected to an accurate ten-step voltage divider network. Internally this chip consists of ten voltage comparators. Vref is independent of the supply voltage. Therefore when the voltage on pin 5 equals 10.5V all ten LEDs will be lit. Since pins 6 and 7 are joined then this is the voltage applied across the internal voltage divider network. For the values shown the voltage is approximately 10.5 volts. ( 1 + R2/R3) + Iadj.R2 The last term is due to a small adjust current (75-120uA) flowing out of pin 8. The total voltage across R2 and R3 is given by V = Vref. Since this voltage is constant then the current through R3 is also constant. The IC develops a nominal 1.25V reference voltage (Vref) across pins 7 and 8. The voltage required to turn on all the LEDs is set by R2 and R3. We have chosen 10.5V to turn on all 10 LED's.

Quasar electronics full#

Two external resistors (R2 & R3 below) programs the full scale from between 1.2V and 12V applied to pin 5. A nominal 1.25V is developed across pins 7 and 8. The IC contains an adjustable voltage reference. In many applications a bargraph meter is faster, more rugged and has higher visibility than an analog (moving coil) or LCD meter. You can download the data sheet from the National Semiconductor website at: The IC is suited to signals with a wide dynamic range such as audio, power, light intensity.

The supply voltage can be between 3V to 25V. The LED drive current is regulated which eliminates the need for current limiting resistors. The display can be bar or moving dot depending on the connection of pin 9 to the positive supply. As the power doubles, an additional LED will be lit until the maximum is reached. When measuring power, a 3dB increase means that the power input has doubled. It takes an analog voltage input on pin 5 then drives 10 LED's providing a logarithmic 3dB/step analog display.

Quasar electronics driver#

This is a monolithic Dot/Bar Display Driver IC made by National Semiconductor. Protel Autotrax & Schematic were used to design it. It contains two identical circuits, one for each channel of the amplifier. The kit is constructed on single-sided printed circuit board. For many situations - disco, parties - this is all which is required: the flashing LED's add atmosphere to the situation.

It is designed to give an approximate visual indication of the audio power output of each channel. This meter is not designed to give an accurate display of the power levels produced by the connected equipment. The levels are displayed in ten discrete steps. QUASAR PROJECT KIT # 3089 - STEREO VU METER This VU (volume-unit) meter is capable of monitoring and displaying power levels present at the speaker terminals of an stereo audio power amplifier.