This is a multi-part message in MIME format. --------------060309000604000406070402 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit John Pearson wrote: > Bob, what do you mean by "the normal part with a resistor"? Thanks > I meant to say "the normally ON part with a resistor". In an RS232 output buffer, typically you invert and the output is low at idle. Using an NPN transistor to do this means there will be current consumption all the time. If you use a PNP transistor, the transistor will be normally off but you still get inversion. Attached is a picture of both types. Please forgive me if I didn't understand what the intended application was, but the diagram should show what I was describing. Cheerful regards, Bob --------------060309000604000406070402 Content-Type: image/gif; name="inverters.gif" Content-Transfer-Encoding: base64 Content-Disposition: inline; filename="inverters.gif" R0lGODlhQAGwALMAAAYFBoiHiEhISMjIyCgoKKioqGdoZ+np6RgYGJiYmFhYWNfY1zg4OLi4 uHh4ePz+/CH5BAAAAAAALAAAAABAAbAAAwT/8MlJq7046827/2AojmRpnmiqrmzrvnAsz3Rt 33iu73zv/8CgcEgsGo/IpHLJbDqf0Kh0Sq1ar9isdsvter/gsHhMLpvP6LR6zW673/C4fE6v JxcBQ8PO708OAQQAAAJ7fodzCwIACAYLiJBsCo8UAAYHkZlrDAoVAwYEmJqjZQkIFggFpKtj BwQWAAGss1+uohMGjIW0vFQLCQ4KiwQMDgN/CYLHvcxOBYMIggoJyxUACc3ZUAiyFwqv2uFM Ag4XDgCU4upHA+kSBwwAt+v0S4b1+Pn6mu77/kAFuv27IQBbhgTF1i04NfBGPAwOEDDolw0T gXINa+SqUCDexHrE/xIAyFijwcgJIhXMWxftwTWSNORJWEAAXL4DqhgIgCljAaGaBRQQupcv AEOeKwoQQDAIAAFVEkwN6pRvwEmkKhYSOHbRAiAAUPEBIIoVRYI9wi4cAKvPUtkWBRDsrLCQ aj4Cc9+uCFBtQgCK9AQw0Es4hYGjhROLiKi4cQijjiN3UDBYsonDJB0UcGDM8gifef8hkCgo rOcPeDMuy9X3dAfBGSMyMu36dWh9JhF0rh1CwG18Qsny/uDb37OVwz/I9Zc2+QjdxgF0amCA M3IXCxoEKNBgQAOM9bj9O+B76aDW2JsOwmsgn/h/ihgpQB9CaTTaM2s+ICdaYFWPBqFwDv9T 0ID3QDGYGFDZPu/hc4BQBABWgmYScNKAAEeBhUkAC+rTYD2LGKgCA1Ap0J5Ly4wlAYf/AECf OAcw9RQLBpyIjgTimTRBA4jl46I/DcTDVgoBXMPAgoLFmNdaAeJj0nX1LCCUhCIsgphPjMyT zD6mkBThDlCK02VGBuA3nHeAiUQSKM49QJ566wmDjZoZCUKhCA1QiYaINTwDwEQHHJCAggwQ KFRGJjEinQiMvHjGADbZkAsCYcIzSJhV2HWEUIQIlcCnCxSwAKZWNZXQGrDZ4AoAIhIVV1Oa atFjEbk4BSec0VQnjG9CEtjUiV8IJ4EAwM7gEwLoZbkfIQRSGsX/AP7BogSWf1ZwQHYBUMbU aNEQiCGcYKxF1XcTzEjDWpFSEE+EQTnV3SB6GlHkLe6shWkQQ4KwVlNyGZDAvVaMJsEzUOUr w1LXrRWXRPlyC8VC6kZ6FRALOFDoegzwaOYGSv5rhgIZvmQwDCIJu98pInV44CLFMoHsBNti ctwPBSzCyEWcOSDIS5DEBfMgzzi6gkQrGljkMktVEIxIAA/BnwQEfCOdVU2/8OB6DgCG5W92 QIyjUYPQYNUyCNi1FrAmGejzyEpsOexgtcqUwwDxfHiBTw8cVnUbNz6QykKzuoDhO6xO8JAE PKo4gQM7CZCuElbhUhkgsYpd9+MHgFIT/yeQHfh4HQR008DeKCwqAc/P7DEAhBL6/MRVQfUA ITZ9D2zivwscNkiZfjdpR0c6+LTMWt0wdXEqGkT+BPI+JB5g6BQgB2lTfAVOR7wvbCTB2A9g 2Qj2yjuhAJ84nBOKuir/AXJTmzlVwMY86RdV3x57EH4T8MheeAWDR687dAMYniBMxhPTPeBo I7jfIUziOwmcYzPCIJAjMpCLloljFxSA31qqUSQS6OgND6KLBVJzgZQdqRhCm8AzKpcNq0TK Khv7oAOtxwGdwUEkwCqSgdZiMp+QToWE8EO0QFA2uS3rcw+QYd5ouAHHzSBPS6iVKNYXoGdo QHEisAoL37AUJv9qQEf7W8s5AKPEDo7ALSK4V+J0gT0VBAl+GGjEcvZDgFyIwowY4NkITALH NSTqTwEg3XLkZ8MgeqV2eNRX7TyAJThiCIkHAxoIxkKn1Jiuc3Hcoge0R4fDmIcQbXzSA57x CAJgg5PWCEsiP4DJD3BiEUeaxATsAjIdmFIQugGYvVxSDvEwLYkTs8CRTqBHOZjyHedwiq+i UZPtlDIvhKCTwi6AxgN6EQOcYFSgmCKoH3GSTjh42YVghZ5rcegkQpmZ39qzlgWEKgCcUYAw OARJD4xJDl5Tl3q65aum3INTdilUA3blG5DZpJUeEKUi3xGAUzLAKuCxYg4WucZUDMD/YssE x77y8gwD2AxX3KolMenQv3fUyoLbC4jvGPBCfnHLV7KATBvLxTWOyU0AstCdyoxog9oNoJ/8 mg9yLlSBdTFiVOYI5hn7eIZJdRFWKgiIBUziHWu6RABNE8lMK9CSc2BiLb853w1w2EW5EDAE jMHAKpcqh0EcSQDyZGoKeNbBRBWkUoYUAbXkigNoMMAAKdTrjy6g0BKwrSECO+BVpHazIxGD KoklwQECuwOsHkyTh50kX+vxjJ2o6R6CCgYn6vZTnmoirdQ0kE9U8oFFwiRlkYNfkYbxwznw EAMkJNxRO4BarPjpGvATUgNJwVLcdihu1+QlYRYgpGI4oEyP/2jXpZjBPQuIdJSDsJkmHWha rHjvVtktaS9ySwFwykixWLSAVc4Kk7x2TzvLuG4v1EkBkzyiVLNJlJnE1Zi/aOAbKHhfHMg7 gcFWRz07q1xxnZM0E2CpnmagKixa9ol+1jG+3T2Nn2RZgiIpyw3DtEb6GFpQgbHGOftyqwmK VCsGBJIN06QAXzqQksx6plS6cVYGDtAAYFBmZ7eqyXo2ywX5gsDDRF4CTWprBX6B98mMGE0s k7EtqCQjvWeoJggWkeQlFIDJVihtOfDAuOrkzAF8GQCUmiVP8yBgq1woEpyXlVwosBcMRt5j MBzHnjuLYRFVi5El6mwZhGqjJRwoUv8oDO2cKSnEKcmz04oILRkPk48Zx2qNoASxFb9QWjID sNKcI2EpiQiGQA9V2qctUyowI2J10SjG6C4g3jZFLx6ubkatbX2AZA6xIYzmzWQTxVqsBLs2 QvpTmXLdjGO7RlDZ+laG/+Fs58wLKeC0NQUq6F2ltqlWw22ID7Xd65pcmiTFHE6KoVFTxKK0 NoGK9zPO/Y+oaZsuriVJNu+dNyXxRAHduF2hytYmQbR7H5xC8IvbpJOy/CIAUOR3cfidGAJT vCx1LMwABKxt6OhlX0SztY0vjm7Kktwfg9VL/bSd8rLAoxH3bvnJkSLzmbf31zZvSFdy3hBX YEMrF+syz1n/YSl+/TUBox76LOLNbKU7/elQjzrJmw6jBAidYwnIFs7DMWJ1KGW7MCNQuElg ilgnfRSrXsW856iBbgTNMec4t7fHMHarOWuXtB5h1wdyKiAW6g/WUAO9W1CeAmOEeQ8IX2W0 TBKJUqBsAH6AVyuhhurYQCTgCfF5tncUSgG6BWdvg6HRQUKhhAbCYAh9CIj34olL50aolZHq IYKIlYQYJegY7F9jMZO5a8MSvomLLPC2CEgtaK0qAITl7SBhmLXsG6lySeZ+pEB1DDMiVAmE BDhloP2BnhgmT0OrDV/ePykObweShxLXEXkKQGoCUprHIjLyDES7xDScApbrYlTEZ3ycQ731 VH36QEpBVF0DUy2GYxOC5nstlG8HBxOM4UKodDqI8VcVsB36MHiEIVKlpWD5JnWrQBkcYBVb B4KZwDivAXYmuIIs2IIu+IIwGIMyOIM0WIM2eIM4mIM6uIM82IM++IN+EAEAOw== --------------060309000604000406070402 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist --------------060309000604000406070402--