"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"I_max=700*10**-3; #in Amperes\n",
"R_ext=0.7/I_max;\n",
"print('value of resistor in Ohms for which max current is 700mA = %f'%R_ext)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"value of resistor in Ohms for which max current is 700mA = 1.000000"
]
}
],
"prompt_number": 8
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"
Example 17.8, Page Number: 572
"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"V_OUT=24.0; #Output voltage in Volts\n",
"R_L=10.0; #Load resistance in Ohms\n",
"V_IN=30.0; #Input voltage in Volts\n",
"I_max=700.0*10**-3; #maximum interal current in Amperes\n",
"I_L=V_OUT/R_L; #load current in amperes\n",
"I_ext=I_L-I_max; #current through the external pass transistor in Amperes\n",
"P_ext_Qext=I_ext*(V_IN-V_OUT); #power dissipated\n",
"print('power dissiated(in WATTS) by the external pass transistor = %.1f'%P_ext_Qext)\n",
"print('\\nFor safety purpose, we choose a power transistor with rating more than this, say 15W')"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"power dissiated(in WATTS) by the external pass transistor = 10.2\n",
"\n",
"For safety purpose, we choose a power transistor with rating more than this, say 15W"
]
}
],
"prompt_number": 9
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"
Example 17.9, Page Number: 574
"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"V_out=5.0; #7805 gives output voltage of 5V\n",
"I_L=1.0; #constant current of 1A\n",
"R1=V_out/I_L;\n",
"print('The value of current-setting resistor in ohms = %d'%R1)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The value of current-setting resistor in ohms = 5"
]
}
],
"prompt_number": 10
}
],
"metadata": {}
}
]
}