在汽车电源电压（12V）内的限制力量电压转换为较高的功率音频放大器。

In fact the max audio power x speaker (with 4 ohm impedance) using 12V is (Vsupply+ - Vsupply-)^2/(8*impedance) 12^2/32 = 4.5Watts per channel, that is laughable...事实上，最大音频功率个扬声器（4欧姆阻抗）使用12V的是（Vsupply + - Vsupply -）^ 2 /（8 *阻抗）12 ^ 2 / 32 = 4.5Watts每通道，这是可笑的...

For powering correctly an amplifier the best is to use a symmetric supply with a high voltage differential.对于放大器供电正确最好是使用具有高电压差分对称供应。 for example +20 - -20 = 40Volts例如，20 - -20 = 40Volts
in fact事实上
40^2/32 = 50 Watts per channel that is respectable. 40 ^ 2 / 32 = 50瓦，每通道是可敬的。

This supply is intended for two channels with 50W max each (of course it depends on the amplifier used).这个供应量是为两个50瓦最大每个（当然，它取决于所用的放大器通道）。 Though it can be easily scaled up or the voltages changed to obtain different values.虽然可以很容易地扩充或更改为获得不同的值的电压。

 概述-它是如何工作

It is a classic push-pull design , taking care to obtain best symmetry (to avoid flux walking).这是一个典型的推拉式设计，以获得最好的照顾对称（以避免流量步行）。 Keep in mind that this circuit will adsorb many amperes (around 10A) so take care to reinforce power tracks with lots of solder and use heavy wires from the battery or the voltage will drop too much at the input.请记住，这个赛道有很多吸附安培（约10A条），因此要注意加强与焊料的大量权力轨道和使用电池或电线的电压将下降沉重的输入太多。

The transformer must be designed to reduce skin effect, it can be done using several insulated magnet wire single wires soldered together but conducting separately.该变压器的设计必须减少皮肤的效果，这是可以做到使用几种漆包线绝缘单线进行焊接在一起，但分开。 The regulation is done both by the transformer turn ratio and varying the duty cycle.规例是由变压器匝比都和不同的占空比。 In my case i used 5+5 , 10+10 turns obtaining a step up ratio of 2 (12->24) and downregulating the voltage to 20 via duty cycle dynamic adjust performed by the PWM controller TL494.在我的情况下，我用5 +5，10 +10转取得了2:1（12 - “24）的步骤，通过占空比下调动态的电压调整执行的20个PWM控制器TL494。

The step-up ratio has to be a little higher to overcome diode losses, winding resistance and so on and input voltage drop due to wire resistance from battery to converter.在升压比例要略高于克服二极管损耗，绕组电阻等输入电压下降和由于导线，从电池到转换器的阻力。

 

Transformer design 变压器设计

The transformer must be of correct size in order to carry the power needed, on the net there are many charts showing the power in function of frequency and core size for a given topology.该变压器必须是正确的大小，以便进行网上显示有一个给定的拓扑结构，在核心频率和功率大小的功能很多图表电力需要。 My transformer size is 33.5 mm lenght, 30.0 height and 13mm width with a cross section area of 1,25cm^2, good for powers around 150W at 50khz.我的变压器的尺寸为33.5 mm长，30.0的高度和宽度13毫米的1,25厘米横截面积^ 2，在50KHz约150瓦的权力好。

The windings , especially the primary must be heavy gauged, but instead of using a single wire it is better to use绕组，特别是主要衡量必须沉重，而是使用了一个单线，最好是使用
multiple wires in parallel each insulated from the other except at the ends.同时在多条线路分别来自除在两端其他绝缘。 This will reduce resistance increase due to skin effect.这将减少阻力的增加，由于皮肤的效果。 The primary and secondary windings are centertapped, this means that you have to wind 5 turns, centertap and 5 windings again.小学和中学绕组centertapped，这意味着你必须风力5转，centertap和5绕组了。 The same goes for the secondary, 10 turns, centertap and 10 turns again.也是一样的中学，10转，centertap和10转了。

The important thing is that the transformer MUST not have air gaps or the leakage inductance will throw spikes on the switches overheating them and giving a voltage higher than expected by turn ratio prediction, so if your voltage output (at fully duty cycle) is higher than Vin*N2/N1 - Vdrop diode, your transformer has gap (of course permit me saying you that you are BLIND if you miss it), and this is accompanied with a drastical efficiency reduction.重要的是，变压器不能有气隙或漏感将引发他们对经济过热，给峰值开关电压高于预期转率的预测，因此如果您的电压输出（在充分占空比）高于葡萄酒* N2/N1 - Vdrop二极管，你的变压器有差距，当然（请允许我说你，你是盲目的，如果你错过了），这是与drastical效率，同时减少。 Use non-gapped E cores or toroids (ferrite).使用非核心或缺口的位置螺旋管（铁素体）。

 

Output diodes, capacitors and filter inductor 输出二极管，电容和滤波电感

For rectification i preferred to use shottky diodes since they have low forward voltage drop, and are incredibly fast.限期整改的首选一使用肖特基二极管，因为它们具有低正向电压降，并且非常快。
I used the cheap 1N5822, the best alternative for low voltage converters (3A for current capability).我使用了廉价的1N5822，对低电压转换器的电流能力（第3A最佳选择）。

The output capacitors are 4700uF 25V, not very big, since at high frequency the voltage ripple is most due to internal cap ESR fortunately general purpose lytics have enough low esr for a small ripple (some tens of millivolts).输出电容4700uF 25V的，不是很大，在高频电压纹波是最幸运的ESR由于通用lytics内部帽，因为有足够的小波纹低ESR（几十毫伏）。 Also at high duty cycle they are feed almost with pure DC, giving small ripple.此外饲料在高占空比它们几乎与纯直流，使小涟漪。 The filter inductor on the secondary centertap furter increases the ripple and helps the regulation in asymmetrical transients关于第二个centertap富尔特尔滤波电感增大了，并有助于在不对称瞬态调节

Power switch and driving 电源开关和驾驶

I used d2pak 70V 80A 0.004 ohms ultrafets (Fairchind semiconductor), very expensive and hard to find.采用D2PAK我用70V的80A条0.004欧姆ultrafets（Fairchind半导体），非常昂贵，而且很难找到。 In principle any fet will work, but the lower the on-resistance, the lower the on-state conduction losses, the lower the heat produced on the fets, the higher efficiency and smaller the heatsinks needed.原则上任何场效应管会的工作，但较低的电阻，较低的状态传导损失，更低的场效应管产生的热量，更高的效率和更小的散热需要。 With this fets i am able to run the fets with small heatsinks and without fan at full rated power (100W) with an efficiency of 82% and perceptible heating and with small heating at 120W (some degrees) (the core starts to saturate and the efficiency is a bit lower, around 75%)有了这个场效应管我能够运行在额定功率（100瓦）小散热片，没有风扇的场效应管在120W的是82％，并明显加热和小热效率（约度）（核心开始饱和的效率有点低75％左右）

Try to use the lowest resistance mosfet you can put your dirty hand :-) on or the efficiency will be lower than rated and you will need even a small fan.尝试使用最低的导通电阻MOSFET，您可以把您的工作效率或肮脏的手:-)将会比排名有所降低，你将有需要，即使一个小风扇。 The fet driver i used is the TPS2811P, from Texas instruments, rated for 2A peak and 200ns. Is important that the gate drive is optimized for minimal inductance or the switching losses will be higher and you risk noise coupling from other sources.场效应管驱动器，是我用了德州仪器TPS2811P，为2A峰值和200ns评价。重要的是，栅极驱