Sebagai negara tropis dan memanjang di katulistiwa, Indonesia sangat diuntungkan dengan adanya paparan irradiasi sinar matahari yang tinggi. Energi ini dapat dipanen dan dimanfaatkan sebagai pengganti energi fosil yang banyak menghasilkan polusi. Sayangnya teknologi ini belum dikenal banyak masyarakat termasuk guru-guru MIPA, cara mengimplementasinya. Sekolah memiliki keuntungan ganda jika memanfaatkan energi matahari ini karena memiliki area yang luas dan beraktivitas pada saat ada paparan sinar matahari. Pada artikel ini dipaparkan aktivitas pelatihan kepada lima guru MIPA SMA Kristen I Salatiga. Ini sebagai wujud pendiseminasian pengetahuan yang dimiliki oleh pengajar dari Fakultas Teknik Elektronika dan Komputer UKSW. Dari hasil kuesioner didapatkan bahwa mereka mendapat pengetahuan baru dan menyatakan bahwa penambangan energi matahari sebenarnya cukup mudah dan akan diterapkan pada sekolah.

The maximum output voltage of the audio amplifier is limited to the magnitude of the power supply voltage of the power transistor or the operational amplifier on the final amplifier. This limits the maximum power of the audio amplifier output. The way to enlarge the output power of the audio amplifier without increasing the voltage is the bridge method or bridged modes. With this method a bridge amplifier will be generated. This Bridge Amplifier is also known as Bridge-Tied Load (BTL) or Bridged Transformerless. The principle of Bridge Amplifiers is to use a pair of final amplifiers whose outputs have opposite phase each other. There are 3 ways to make a pair of power amplifiers have opposing phases: with internal modification, with an audio transformer (phase splitting audio input transformer) and with a simple active phase reversal splitter circuit). This paper will discuss Bridge Amplifiers with simple phase inverting circuits. A pair of audio power amplifiers using two TDA2050 chips which are operated at ± 19 Volt supply voltage. The phase inverting circuit using IC TL072. Sinusoidal signal with an amplitude of 200 mVp and a frequency of 1 KHz is used as an input signal. The results to be observed and measured are gain, input, output and bandwidth of the bridged amplifier compared to the usual amplifier

A class D amplifier is one in which the output transistors are operated as switches. When a transistor is off, the current through it is zero and when it is on, the voltage across it is small, ideally zero. Thus the power dissipation is very low, so it requires a smaller heat sink for the amplifier. Class D amplifier operation is based on analog principles and there is no digital encoding of the signal. Before the emergence of class D amplifiers, the standard classes were class A, class AB, class B, and class C. The classic method for generating signals driving a transistor MOSFET is to use a comparator. One input is driven by an incoming audio signal, and the other by a triangle wave or a sawtooth wave at the required switching frequency. The frequency of a triangular or sawtooth wave must be higher than the audio input. MOSFET transistors work in a complementary manner that operates as a switch. Triangle waves are usually generated by square waves fed to the integrator circuit. So the main part of processing audio signals into PWM (Pulse Width Modulation) is the integrator and comparator. In this paper, we will discuss the work of a class D amplifier system using the summing integrator method as its main part.